A vulnerability in certain attachment detection mechanisms of Cisco Email Security Appliances (ESA) could allow an unauthenticated, remote attacker to bypass the filtering functionality of an affected system. The vulnerability is due to the improper detection of content within executable (EXE) files. An attacker could exploit this vulnerability by sending a customized EXE file that is not recognized and blocked by the ESA. A successful exploit could allow an attacker to send email messages that contain malicious executable files to unsuspecting users. Cisco Bug IDs: CSCvh03786.

A vulnerability in the file type detection mechanism of the Cisco Advanced Malware Protection (AMP) for Endpoints macOS Connector could allow an unauthenticated, remote attacker to bypass malware detection. The vulnerability occurs because the software relies on only the file extension for detecting DMG files. An attacker could exploit this vulnerability by sending a DMG file with a nonstandard extension to a device that is running an affected AMP for Endpoints macOS Connector. An exploit could allow the attacker to bypass configured malware detection. Cisco Bug IDs: CSCve34034.

A vulnerability in the detection engine of Cisco Firepower Threat Defense software could allow an unauthenticated, remote attacker to bypass a configured Secure Sockets Layer (SSL) Access Control (AC) policy to block SSL traffic. The vulnerability is due to the incorrect handling of TCP SSL packets received out of order. An attacker could exploit this vulnerability by sending a crafted SSL connection through the affected device. A successful exploit could allow the attacker to bypass a configured SSL AC policy to block SSL traffic. Cisco Bug IDs: CSCvg09316.

A vulnerability in the anti-spam protection mechanisms of Cisco AsyncOS Software for the Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass certain content filters on an affected device. The vulnerability is due to incomplete input and validation checking mechanisms for certain Sender Policy Framework (SPF) messages that are sent to an affected device. An attacker could exploit this vulnerability by sending a customized SPF packet to an affected device. If successful, an exploit could allow the attacker to bypass the URL filters that are configured for the affected device, which could allow malicious URLs to pass through the device.

A vulnerability in the SMTP relay of Cisco Unity Connection could allow an unauthenticated, remote attacker to send unsolicited email messages, aka a Mail Relay Vulnerability. The vulnerability is due to improper handling of domain information in the affected software. An unauthenticated, remote attacker could exploit this vulnerability by sending crafted requests to the targeted application. A successful exploit could allow the attacker to send email messages to arbitrary addresses. Cisco Bug IDs: CSCvg62215.

A vulnerability in the detection engine of Cisco Firepower System Software could allow an unauthenticated, remote attacker to bypass configured file action policies if an Intelligent Application Bypass (IAB) with a drop percentage threshold is also configured. The vulnerability is due to incorrect counting of the percentage of dropped traffic. An attacker could exploit this vulnerability by sending network traffic to a targeted device. An exploit could allow the attacker to bypass configured file action policies, and traffic that should be dropped could be allowed into the network. Cisco Bug IDs: CSCvf86435.

Cisco NX-OS on the Nexus 1000V does not properly handle authentication for Virtual Ethernet Module (VEM) to Virtual Supervisor Module (VSM) communication, which allows remote attackers to obtain VEM access via (1) spoofed STUN packets or (2) a crafted VMware ESXi instance, aka Bug ID CSCud14832.

The Comcast firmware on Cisco DPC3939 (firmware version dpc3939-P20-18-v303r20421746-170221a-CMCST) devices allows remote attackers to write arbitrary data to a known /var/tmp/sess_* pathname by leveraging the device's operation in UI dev mode.

The encryption functionality in the Virtual Supervisor Module (VSM) to Virtual Ethernet Module (VEM) communication component in Cisco NX-OS on the Nexus 1000V does not properly authenticate VSM/VEM packets, which allows remote attackers to disable packet-level encryption and integrity protection via crafted packets, aka Bug ID CSCud14710.

Cisco IOS 11.1CC through 12.2 with Cisco Express Forwarding (CEF) enabled includes portions of previous packets in the padding of a MAC level packet when the MAC packet's length is less than the IP level packet length.

A vulnerability in the Secure Sockets Layer (SSL)/Transport Layer Security (TLS) protocol inspection engine of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass the configured file policies on an affected system. The vulnerability is due to errors when handling specific SSL/TLS messages. An attacker could exploit this vulnerability by sending crafted HTTP packets that would flow through an affected system. A successful exploit could allow the attacker to bypass the configured file policies and deliver a malicious payload to the protected network.

A vulnerability in the GZIP decompression engine of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass configured content filters on the device. The vulnerability is due to improper validation of GZIP-formatted files. An attacker could exploit this vulnerability by sending a malicious file inside a crafted GZIP-compressed file. A successful exploit could allow the attacker to bypass configured content filters that would normally drop the email.

A vulnerability in Cisco TelePresence Video Communication Server (VCS) and Cisco Expressway Series software could allow an unauthenticated, remote attacker to cause an affected system to send arbitrary network requests. The vulnerability is due to improper restrictions on network services in the affected software. An attacker could exploit this vulnerability by sending malicious requests to the affected system. A successful exploit could allow the attacker to send arbitrary network requests sourced from the affected system.

A vulnerability in the attachment scanning of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass configured content filters on the device. The vulnerability is due to improper input validation of the email body. An attacker could exploit this vulnerability by naming a malicious attachment with a specific pattern. A successful exploit could allow the attacker to bypass configured content filters that would normally block the attachment.

A vulnerability in the normalization functionality of Cisco Firepower Threat Defense Software, Cisco FirePOWER Services Software for ASA, and Cisco Firepower Management Center Software could allow an unauthenticated, remote attacker to bypass filtering protections. The vulnerability is due to insufficient normalization of a text-based payload. An attacker could exploit this vulnerability by sending traffic that contains specifically obfuscated payloads through an affected device. An exploit could allow the attacker to bypass filtering and deliver malicious payloads to protected systems that would otherwise be blocked.

A vulnerability in the Sender Policy Framework (SPF) functionality of Cisco AsyncOS Software for Cisco Email Security Appliances (ESA) could allow an unauthenticated, remote attacker to bypass configured user filters on the device. The vulnerability is due to incomplete input and validation checking mechanisms for certain SPF messages that are sent to an affected device. An attacker could exploit this vulnerability by sending a customized SPF packet to an affected device. A successful exploit could allow the attacker to bypass the header filters that are configured for the affected device, which could allow malicious content to pass through the device.

A vulnerability in the HTTP traffic filtering component of Cisco Firepower Threat Defense Software, Cisco FirePOWER Services Software for ASA, and Cisco Firepower Management Center Software could allow an unauthenticated, remote attacker to bypass filtering protections. The vulnerability is due to improper handling of HTTP requests, including those communicated over a secure HTTPS connection, that contain maliciously crafted headers. An attacker could exploit this vulnerability by sending malicious requests to an affected device. An exploit could allow the attacker to bypass filtering and deliver malicious requests to protected systems, allowing attackers to deliver malicious content that would otherwise be blocked.

A vulnerability in the packet filtering features of Cisco SD-WAN Solution could allow an unauthenticated, remote attacker to bypass L3 and L4 traffic filters. The vulnerability is due to improper traffic filtering conditions on an affected device. An attacker could exploit this vulnerability by crafting a malicious TCP packet with specific characteristics and sending it to a target device. A successful exploit could allow the attacker to bypass the L3 and L4 traffic filters and inject an arbitrary packet in the network.

The Comcast firmware on Cisco DPC3939 (firmware version dpc3939-P20-18-v303r20421746-170221a-CMCST) devices allows remote attackers to obtain unintended access to the Network Processor (NP) 169.254/16 IP network by adding a routing-table entry that specifies the LAN IP address as the router for that network.

A vulnerability in the implementation of Security Assertion Markup Language (SAML) 2.0 Single Sign-On (SSO) for Clientless SSL VPN (WebVPN) and AnyConnect Remote Access VPN in Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to successfully establish a VPN session to an affected device. The vulnerability is due to improper credential management when using NT LAN Manager (NTLM) or basic authentication. An attacker could exploit this vulnerability by opening a VPN session to an affected device after another VPN user has successfully authenticated to the affected device via SAML SSO. A successful exploit could allow the attacker to connect to secured networks behind the affected device.

A vulnerability in access control list (ACL) functionality of the Gigabit Ethernet Management interface of Cisco IOS XE Software could allow an unauthenticated, remote attacker to reach the configured IP addresses on the Gigabit Ethernet Management interface. The vulnerability is due to a logic error that was introduced in the Cisco IOS XE Software 16.1.1 Release, which prevents the ACL from working when applied against the management interface. An attacker could exploit this issue by attempting to access the device via the management interface.

A vulnerability in the detection engine of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured access control policies. The vulnerability is due to improper validation of ICMP packets. An attacker could exploit this vulnerability by sending crafted ICMP packets to the affected device. A successful exploit could allow the attacker to bypass configured access control policies.

A vulnerability in certain attachment detection mechanisms of the Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass the filtering functionality of an affected device. The vulnerability is due to improper detection of certain content sent to an affected device. An attacker could exploit this vulnerability by sending certain file types without Content-Disposition information to an affected device. A successful exploit could allow an attacker to send messages that contain malicious content to users.

A vulnerability in the Secure Sockets Layer (SSL)/Transport Layer Security (TLS) protocol parser of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured policies. The vulnerability is due to improper parsing of specific attributes in a TLS packet header. An attacker could exploit this vulnerability by sending malicious TLS messages to the affected system. A successful exploit could allow the attacker to bypass the configured policies for the system, which could allow traffic to flow through without being inspected.

A vulnerability in the access-control logic of the NETCONF over Secure Shell (SSH) of Cisco IOS XR Software may allow connections despite an access control list (ACL) that is configured to deny access to the NETCONF over SSH of an affected device. The vulnerability is due to a missing check in the NETCONF over SSH access control list (ACL). An attacker could exploit this vulnerability by connecting to an affected device using NETCONF over SSH. A successful exploit could allow the attacker to connect to the device on the NETCONF port. Valid credentials are required to access the device. This vulnerability does not affect connections to the default SSH process on the device.

A vulnerability in the TCP flags inspection feature for access control lists (ACLs) on Cisco ASR 9000 Series Aggregation Services Routers could allow an unauthenticated, remote attacker to bypass protection offered by a configured ACL on an affected device. The vulnerability is due to incorrect processing of the ACL applied to an interface of an affected device when Cisco Express Forwarding load balancing using the 3-tuple hash algorithm is enabled. An attacker could exploit this vulnerability by sending traffic through an affected device that should otherwise be denied by the configured ACL. An exploit could allow the attacker to bypass protection offered by a configured ACL on the affected device. There are workarounds that address this vulnerability. Affected Cisco IOS XR versions are: Cisco IOS XR Software Release 5.1.1 and later till first fixed. First Fixed Releases: 6.5.2 and later, 6.6.1 and later.

A vulnerability in the configuration import utility of Cisco Integrated Management Controller (IMC) could allow an unauthenticated, remote attacker to have write access and upload arbitrary data to the filesystem. The vulnerability is due to a failure to delete temporarily uploaded files. An attacker could exploit this vulnerability by crafting a malicious file and uploading it to the affected device. An exploit could allow the attacker to fill up the filesystem or upload malicious scripts.

The Neighbor Discovery (ND) protocol implementation in Cisco IOS on unspecified switches allows remote attackers to bypass the Router Advertisement Guarding functionality via a fragmented IPv6 packet in which the Router Advertisement (RA) message is contained in the second fragment, as demonstrated by (1) a packet in which the first fragment contains a long Destination Options extension header or (2) a packet in which the first fragment contains an ICMPv6 Echo Request message.

A vulnerability in the antispam protection mechanisms of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass the URL reputation filters on an affected device. The vulnerability is due to insufficient input validation of URLs. An attacker could exploit this vulnerability by crafting the URL in a particular way. A successful exploit could allow the attacker to bypass the URL reputation filters that are configured for the affected device, which could allow malicious URLs to pass through the device.

A vulnerability in the web proxy functionality of the Cisco Web Security Appliance (WSA) could allow an unauthenticated, remote attacker to forward traffic from the web proxy interface of an affected device to the administrative management interface of an affected device, aka an Access Control Bypass Vulnerability. Affected Products: virtual and hardware versions of Cisco Web Security Appliance (WSA). More Information: CSCvd88863. Known Affected Releases: 10.1.0-204 9.0.0-485.

A vulnerability in the gateway GPRS support node (GGSN) of Cisco ASR 5000 Series Aggregation Services Routers 17.3.9.62033 through 21.1.2 could allow an unauthenticated, remote attacker to redirect HTTP traffic sent to an affected device. More Information: CSCvc67927.

A vulnerability in the Secure Sockets Layer (SSL) Decryption and Inspection feature of Cisco Firepower System Software 5.4.0, 5.4.1, 6.0.0, 6.1.0, 6.2.0, 6.2.1, and 6.2.2 could allow an unauthenticated, remote attacker to bypass the SSL policy for decrypting and inspecting traffic on an affected system. The vulnerability is due to unexpected interaction with Known Key and Decrypt and Resign configuration settings of SSL policies when the affected software receives unexpected SSL packet headers. An attacker could exploit this vulnerability by sending a crafted SSL packet through an affected device in a valid SSL session. A successful exploit could allow the attacker to bypass the SSL decryption and inspection policy for the affected system, which could allow traffic to flow through the system without being inspected. Cisco Bug IDs: CSCve12652.

A vulnerability in the AutoVNF logging function of Cisco Ultra Services Framework could allow an unauthenticated, remote attacker to create arbitrary directories on the affected system. More Information: CSCvc76652. Known Affected Releases: 21.0.0.

A vulnerability in the feature-license management functionality of Cisco Firepower System Software could allow an unauthenticated, remote attacker to bypass URL filters that have been configured for an affected device. More Information: CSCvb16413. Known Affected Releases: 6.0.1 6.1.0 6.2.0 6.2.1. Known Fixed Releases: 6.2.1 6.2.0.1 6.1.0.2.

A vulnerability in the email message scanning of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass configured filters on the device, as demonstrated by the Attachment Filter. More Information: CSCvd34632. Known Affected Releases: 10.0.1-087 9.7.1-066. Known Fixed Releases: 10.0.2-020 9.8.1-015.

A vulnerability in the Dialer interface feature for ISDN connections in Cisco IOS XE Software for Cisco 4000 Series Integrated Services Routers (ISRs) could allow an unauthenticated, adjacent attacker to pass IPv4 traffic through an ISDN channel prior to successful PPP authentication. The vulnerability is due to insufficient validation of the state of the PPP IP Control Protocol (IPCP). An attacker could exploit this vulnerability by making an ISDN call to an affected device and sending traffic through the ISDN channel prior to successful PPP authentication. Alternatively, an unauthenticated, remote attacker could exploit this vulnerability by sending traffic through an affected device that is configured to exit via an ISDN connection for which both the Dialer interface and the Basic Rate Interface (BRI) have been configured, but the Challenge Handshake Authentication Protocol (CHAP) password for PPP does not match the remote end. A successful exploit could allow the attacker to pass IPv4 traffic through an unauthenticated ISDN connection for a few seconds, from initial ISDN call setup until PPP authentication fails.

Multiple vulnerabilities in the Cisco Firepower System Software Detection Engine could allow an unauthenticated, remote attacker to bypass configured Malware and File Policies for RTF and RAR file types. For more information about these vulnerabilities, see the Details section of this advisory.

A vulnerability in the file and malware inspection feature of Cisco Firepower Management Center (FMC) Software could allow an unauthenticated, remote attacker to bypass the file and malware inspection policies on an affected system. The vulnerability exists because the affected software insufficiently validates incoming traffic. An attacker could exploit this vulnerability by sending a crafted HTTP request through an affected device. A successful exploit could allow the attacker to bypass the file and malware inspection policies and send malicious traffic through the affected device.

A vulnerability in the Sender Policy Framework (SPF) functionality of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass the configured user filters on an affected device. The vulnerability exists because the affected software insufficiently validates certain incoming SPF messages. An attacker could exploit this vulnerability by sending a custom SPF packet to an affected device. A successful exploit could allow the attacker to bypass the configured header filters, which could allow malicious content to pass through the device.

The Management Interface on Cisco Content Services Switch (CSS) 11500 devices 8.20.4.02 and earlier allows remote attackers to bypass intended restrictions on local-network device access via crafted SSH packets, aka Bug ID CSCut14855.

A vulnerability in the Autonomic Networking feature of Cisco IOS XE Software could allow an unauthenticated, remote, autonomic node to access the Autonomic Networking infrastructure of an affected system, after the certificate for the autonomic node has been revoked. This vulnerability affected devices that are running Release 16.x of Cisco IOS XE Software and are configured to use Autonomic Networking. This vulnerability does not affect devices that are running an earlier release of Cisco IOS XE Software or devices that are not configured to use Autonomic Networking. More Information: CSCvd22328. Known Affected Releases: 15.5(1)S3.1 Denali-16.2.1.

A vulnerability in Cisco Unified Contact Center Express (Unified CCX) could allow an unauthenticated, remote attacker to bypass access controls and conduct a server-side request forgery (SSRF) attack on a targeted system. The vulnerability is due to improper validation of user-supplied input on the affected system. An attacker could exploit this vulnerability by sending the user of the web application a crafted request. If the request is processed, the attacker could access the system and perform unauthorized actions.

A vulnerability in the statistics collection service of Cisco HyperFlex Software could allow an unauthenticated, remote attacker to inject arbitrary values on an affected device. The vulnerability is due to insufficient authentication for the statistics collection service. An attacker could exploit this vulnerability by sending properly formatted data values to the statistics collection service of an affected device. A successful exploit could allow the attacker to cause the web interface statistics view to present invalid data to users.

A vulnerability in the Multipurpose Internet Mail Extensions (MIME) scanner of Cisco AsyncOS Software for Cisco Email Security Appliances (ESA) could allow an unauthenticated, remote attacker to bypass configured user filters on the device. The vulnerability is due to improper error handling of a malformed MIME header in an email attachment. An attacker could exploit this vulnerability by sending an email with a crafted MIME attachment. For example, a successful exploit could allow the attacker to bypass configured user filters to drop the email. The malformed MIME headers may not be RFC compliant. However, some mail clients could still allow users to access the attachment, which may not have been properly filtered by the device. Cisco Bug IDs: CSCvf44666.

A vulnerability in the Multipurpose Internet Mail Extensions (MIME) scanner of Cisco AsyncOS Software for Cisco Email Security Appliances (ESA) and Web Security Appliances (WSA) could allow an unauthenticated, remote attacker to bypass configured user filters on the device. Affected Products: This vulnerability affects all releases prior to the first fixed release of Cisco AsyncOS Software for Cisco ESA and Cisco WSA, both virtual and hardware appliances, that are configured with message or content filters to scan incoming email attachments on the ESA or services scanning content of web access on the WSA. More Information: SCvb91473, CSCvc76500. Known Affected Releases: 10.0.0-203 9.9.9-894 WSA10.0.0-233.

A vulnerability in the URL filtering feature of Cisco AsyncOS Software for Cisco Web Security Appliance (WSA) could allow an unauthenticated, remote attacker to bypass a configured URL filter rule. Affected Products: This vulnerability affects all releases prior to the first fixed release of Cisco AsyncOS Software for Cisco Web Security Appliance (WSA), both virtual and hardware appliances, that are configured with URL filters for email scanning. More Information: CSCvc69700. Known Affected Releases: 8.5.3-069 9.1.1-074 9.1.2-010.

An Access-Control Filtering Mechanisms Bypass vulnerability in certain access-control filtering mechanisms on Cisco Nexus 7000 Series Switches could allow an unauthenticated, remote attacker to bypass defined traffic configured within an access control list (ACL) on the affected system. More Information: CSCtz59354. Known Affected Releases: 5.2(4) 6.1(3)S5 6.1(3)S6 6.2(1.121)S0 7.2(1)D1(1) 7.3(0)ZN(0.161) 7.3(1)N1(0.1). Known Fixed Releases: 7.3(0)D1(1) 6.2(2) 6.1(5) 8.3(0)KMT(0.24) 8.3(0)CV(0.337) 7.3(1)N1(1) 7.3(0)ZN(0.210) 7.3(0)ZN(0.177) 7.3(0)ZD(0.194) 7.3(0)TSH(0.99) 7.3(0)SC(0.14) 7.3(0)RSP(0.7) 7.3(0)N1(1) 7.3(0)N1(0.193) 7.3(0)IZN(0.13) 7.3(0)IB(0.102) 7.3(0)GLF(0.44) 7.3(0)D1(0.178) 7.1(0)D1(0.14) 7.0(3)ITI2(1.6) 7.0(3)ISH1(2.13) 7.0(3)IFD6(0.78) 7.0(3)IFD6(0) 7.0(3)IDE6(0.12) 7.0(3)IDE6(0) 7.0(3)I2(1) 7.0(3)I2(0.315) 7.0(1)ZD(0.3) 7.0(0)ZD(0.84) 6.2(1.149)S0 6.2(0.285) 6.1(5.32)S0 6.1(4.97)S0 6.1(2.30)S0.