A hash collision flaw was found in the IPv6 connection lookup table in the Linux kernel’s IPv6 functionality when a user makes a new kind of SYN flood attack. A user located in the local network or with a high bandwidth connection can increase the CPU usage of the server that accepts IPV6 connections up to 95%.

A Denial of Service (DoS) condition is possible in OpenStack Mistral in versions up to and including 7.0.3. Submitting a specially crafted workflow definition YAML file containing nested anchors can lead to resource exhaustion culminating in a denial of service.

In Apache HTTP server versions 2.4.37 and prior, by sending request bodies in a slow loris way to plain resources, the h2 stream for that request unnecessarily occupied a server thread cleaning up that incoming data. This affects only HTTP/2 (mod_http2) connections.

An uncontrolled resource consumption vulnerability was discovered in HAProxy which could crash the service. This issue could allow an authenticated remote attacker to run a specially crafted malicious server in an OpenShift cluster. The biggest impact is to availability.

A flaw was found in pacemaker up to and including version 2.0.1. An insufficient verification inflicted preference of uncontrolled processes can lead to DoS

NTP before 4.2.8p9 rate limits responses received from the configured sources when rate limiting for all associations is enabled, which allows remote attackers to cause a denial of service (prevent responses from the sources) by sending responses with a spoofed source address.

A flaw was found in 389 Directory Server. A specially crafted search query could lead to excessive CPU consumption in the do_search() function. An unauthenticated attacker could use this flaw to provoke a denial of service.

The mod_dontdothat component of the mod_dav_svn Apache module in Subversion as packaged in Red Hat Enterprise Linux 5.11 does not properly detect recursion during entity expansion, which allows remote authenticated users with access to the webdav repository to cause a denial of service (memory consumption and httpd crash). NOTE: Exists as a regression to CVE-2009-1955.

A flaw was found in glusterfs server through versions 4.1.4 and 3.1.2 which allowed repeated usage of GF_META_LOCK_KEY xattr. A remote, authenticated attacker could use this flaw to create multiple locks for single inode by using setxattr repetitively resulting in memory exhaustion of glusterfs server node.

systemd 250 and 251 allows local users to achieve a systemd-coredump deadlock by triggering a crash that has a long backtrace. This occurs in parse_elf_object in shared/elf-util.c. The exploitation methodology is to crash a binary calling the same function recursively, and put it in a deeply nested directory to make its backtrace large enough to cause the deadlock. This must be done 16 times when MaxConnections=16 is set for the systemd/units/systemd-coredump.socket file.

A flaw was found in gnome-remote-desktop. Once gnome-remote-desktop listens for RDP connections, an unauthenticated attacker can exhaust system resources and repeatedly crash the process. There may be a resource leak after many attacks, which will also result in gnome-remote-desktop no longer being able to open files even after it is restarted via systemd.

Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Prior to version 7.0.3, excessive memory use during pgsql parsing could lead to OOM-related crashes. This vulnerability is patched in 7.0.3. As workaround, users can disable the pgsql app layer parser.

The virtqueue_pop function in hw/virtio/virtio.c in QEMU allows local guest OS administrators to cause a denial of service (memory consumption and QEMU process crash) by submitting requests without waiting for completion.

The ehci_advance_state function in hw/usb/hcd-ehci.c in QEMU allows local guest OS administrators to cause a denial of service (infinite loop and CPU consumption) via a circular split isochronous transfer descriptor (siTD) list, a related issue to CVE-2015-8558.

A flaw was found in jboss-remoting in versions before 5.0.20.SP1-redhat-00001. A malicious attacker could cause threads to hold up forever in the EJB server by writing a sequence of bytes corresponding to the expected messages of a successful EJB client request, but omitting the ACK messages, or just tamper with jboss-remoting code, deleting the lines that send the ACK message from the EJB client code resulting in a denial of service. The highest threat from this vulnerability is to system availability.

A flaw was found in the Undertow AJP connector. Malicious requests and abrupt connection closes could be triggered by an attacker using query strings with non-RFC compliant characters resulting in a denial of service. The highest threat from this vulnerability is to system availability. This affects Undertow 2.1.5.SP1, 2.0.33.SP2, and 2.2.3.SP1.

strongSwan before 5.9.8 allows remote attackers to cause a denial of service in the revocation plugin by sending a crafted end-entity (and intermediate CA) certificate that contains a CRL/OCSP URL that points to a server (under the attacker's control) that doesn't properly respond but (for example) just does nothing after the initial TCP handshake, or sends an excessive amount of application data.

Nextcloud server is an open source personal cloud server. Affected versions of nextcloud server did not properly limit user display names which could allow a malicious users to overload the backing database and cause a denial of service. It is recommended that the Nextcloud Server is upgraded to 22.2.10, 23.0.7 or 24.0.3. There are no known workarounds for this issue.

cmark-gfm is GitHub's fork of cmark, a CommonMark parsing and rendering library and program in C. In versions prior to 0.29.0.gfm.6 a polynomial time complexity issue in cmark-gfm's autolink extension may lead to unbounded resource exhaustion and subsequent denial of service. Users may verify the patch by running `python3 -c 'print("![l"* 100000 + "\n")' | ./cmark-gfm -e autolink`, which will resource exhaust on unpatched cmark-gfm but render correctly on patched cmark-gfm. This vulnerability has been patched in 0.29.0.gfm.6. Users are advised to upgrade. Users unable to upgrade should disable the use of the autolink extension.

Rust-WebSocket is a WebSocket (RFC6455) library written in Rust. In versions prior to 0.26.5 untrusted websocket connections can cause an out-of-memory (OOM) process abort in a client or a server. The root cause of the issue is during dataframe parsing. Affected versions would allocate a buffer based on the declared dataframe size, which may come from an untrusted source. When `Vec::with_capacity` fails to allocate, the default Rust allocator will abort the current process, killing all threads. This affects only sync (non-Tokio) implementation. Async version also does not limit memory, but does not use `with_capacity`, so DoS can happen only when bytes for oversized dataframe or message actually got delivered by the attacker. The crashes are fixed in version 0.26.5 by imposing default dataframe size limits. Affected users are advised to update to this version. Users unable to upgrade are advised to filter websocket traffic externally or to only accept trusted traffic.

nghttp2 before 1.7.1 allows remote attackers to cause a denial of service (memory exhaustion).

A flaw was found in multiple versions of OpenvSwitch. Specially crafted LLDP packets can cause memory to be lost when allocating data to handle specific optional TLVs, potentially causing a denial of service. The highest threat from this vulnerability is to system availability.

A vulnerability was found in the minimatch package. This flaw allows a Regular Expression Denial of Service (ReDoS) when calling the braceExpand function with specific arguments, resulting in a Denial of Service.

An uncontrolled resource consumption flaw was found in openstack-neutron. This flaw allows a remote authenticated user to query a list of security groups for an invalid project. This issue creates resources that are unconstrained by the user's quota. If a malicious user were to submit a significant number of requests, this could lead to a denial of service.

By specially crafting HTTP/2 requests, workers would be allocated 60 seconds longer than necessary, leading to worker exhaustion and a denial of service. Fixed in Apache HTTP Server 2.4.34 (Affected 2.4.18-2.4.30,2.4.33).

Node.js: All versions prior to Node.js 6.15.0, 8.14.0, 10.14.0 and 11.3.0: Denial of Service with large HTTP headers: By using a combination of many requests with maximum sized headers (almost 80 KB per connection), and carefully timed completion of the headers, it is possible to cause the HTTP server to abort from heap allocation failure. Attack potential is mitigated by the use of a load balancer or other proxy layer.

It was found that URLResource.getLastModified() in Undertow closes the file descriptors only when they are finalized which can cause file descriptors to exhaust. This leads to a file handler leak.

libvirt version before 4.2.0-rc1 is vulnerable to a resource exhaustion as a result of an incomplete fix for CVE-2018-5748 that affects QEMU monitor but now also triggered via QEMU guest agent.

It was discovered that fsync(2) system call in glusterfs client code leaks memory. An authenticated attacker could use this flaw to launch a denial of service attack by making gluster clients consume memory of the host machine.

When a POST request comes through AJP and the request exceeds the max-post-size limit (maxEntitySize), Undertow's AjpServerRequestConduit implementation closes a connection without sending any response to the client/proxy. This behavior results in that a front-end proxy marking the backend worker (application server) as an error state and not forward requests to the worker for a while. In mod_cluster, this continues until the next STATUS request (10 seconds intervals) from the application server updates the server state. So, in the worst case, it can result in "All workers are in error state" and mod_cluster responds "503 Service Unavailable" for a while (up to 10 seconds). In mod_proxy_balancer, it does not forward requests to the worker until the "retry" timeout passes. However, luckily, mod_proxy_balancer has "forcerecovery" setting (On by default; this parameter can force the immediate recovery of all workers without considering the retry parameter of the workers if all workers of a balancer are in error state.). So, unlike mod_cluster, mod_proxy_balancer does not result in responding "503 Service Unavailable". An attacker could use this behavior to send a malicious request and trigger server errors, resulting in DoS (denial of service). This flaw was fixed in Undertow 2.2.19.Final, Undertow 2.3.0.Alpha2.

An uncontrolled resource consumption flaw has been discovered in redhat-certification in the way documents are loaded. A remote attacker may provide an existing but invalid XML file which would be opened and never closed, possibly producing a Denial of Service.

containerd is an open source container runtime. A bug was found in the containerd's CRI implementation where programs inside a container can cause the containerd daemon to consume memory without bound during invocation of the `ExecSync` API. This can cause containerd to consume all available memory on the computer, denying service to other legitimate workloads. Kubernetes and crictl can both be configured to use containerd's CRI implementation; `ExecSync` may be used when running probes or when executing processes via an "exec" facility. This bug has been fixed in containerd 1.6.6 and 1.5.13. Users should update to these versions to resolve the issue. Users unable to upgrade should ensure that only trusted images and commands are used.

Memcached version 1.5.5 contains an Insufficient Control of Network Message Volume (Network Amplification, CWE-406) vulnerability in the UDP support of the memcached server that can result in denial of service via network flood (traffic amplification of 1:50,000 has been reported by reliable sources). This attack appear to be exploitable via network connectivity to port 11211 UDP. This vulnerability appears to have been fixed in 1.5.6 due to the disabling of the UDP protocol by default.

This affects the package jinja2 from 0.0.0 and before 2.11.3. The ReDoS vulnerability is mainly due to the `_punctuation_re regex` operator and its use of multiple wildcards. The last wildcard is the most exploitable as it searches for trailing punctuation. This issue can be mitigated by Markdown to format user content instead of the urlize filter, or by implementing request timeouts and limiting process memory.

moment is a JavaScript date library for parsing, validating, manipulating, and formatting dates. Affected versions of moment were found to use an inefficient parsing algorithm. Specifically using string-to-date parsing in moment (more specifically rfc2822 parsing, which is tried by default) has quadratic (N^2) complexity on specific inputs. Users may notice a noticeable slowdown is observed with inputs above 10k characters. Users who pass user-provided strings without sanity length checks to moment constructor are vulnerable to (Re)DoS attacks. The problem is patched in 2.29.4, the patch can be applied to all affected versions with minimal tweaking. Users are advised to upgrade. Users unable to upgrade should consider limiting date lengths accepted from user input.

A vulnerability was discovered in XNIO where file descriptor leak caused by growing amounts of NIO Selector file handles between garbage collection cycles. It may allow the attacker to cause a denial of service. It affects XNIO versions 3.6.0.Beta1 through 3.8.1.Final.

A vulnerability was found in CRI-O that causes memory or disk space exhaustion on the node for anyone with access to the Kube API. The ExecSync request runs commands in a container and logs the output of the command. This output is then read by CRI-O after command execution, and it is read in a manner where the entire file corresponding to the output of the command is read in. Thus, if the output of the command is large it is possible to exhaust the memory or the disk space of the node when CRI-O reads the output of the command. The highest threat from this vulnerability is system availability.

Matrix is an ecosystem for open federated Instant Messaging and VoIP. Synapse is a reference "homeserver" implementation of Matrix. A malicious or poorly-implemented homeserver can inject malformed events into a room by specifying a different room id in the path of a `/send_join`, `/send_leave`, `/invite` or `/exchange_third_party_invite` request. This can lead to a denial of service in which future events will not be correctly sent to other servers over federation. This affects any server which accepts federation requests from untrusted servers. The Matrix Synapse reference implementation before version 1.23.1 the implementation is vulnerable to this injection attack. Issue is fixed in version 1.23.1. As a workaround homeserver administrators could limit access to the federation API to trusted servers (for example via `federation_domain_whitelist`).

A denial of service vulnerability exists when .NET Framework and .NET Core improperly process RegEx strings, aka '.NET Framework and .NET Core Denial of Service Vulnerability'. This CVE ID is unique from CVE-2019-0980, CVE-2019-0981.

The Moped::BSON::ObjecId.legal? method in mongodb/bson-ruby before 3.0.4 as used in rubygem-moped allows remote attackers to cause a denial of service (worker resource consumption) via a crafted string. NOTE: This issue is due to an incomplete fix to CVE-2015-4410.

The Linux kernel, versions 3.9+, is vulnerable to a denial of service attack with low rates of specially modified packets targeting IP fragment re-assembly. An attacker may cause a denial of service condition by sending specially crafted IP fragments. Various vulnerabilities in IP fragmentation have been discovered and fixed over the years. The current vulnerability (CVE-2018-5391) became exploitable in the Linux kernel with the increase of the IP fragment reassembly queue size.

PowerDNS Recursor from 4.1.0 up to and including 4.3.0 does not sufficiently defend against amplification attacks. An issue in the DNS protocol has been found that allow malicious parties to use recursive DNS services to attack third party authoritative name servers. The attack uses a crafted reply by an authoritative name server to amplify the resulting traffic between the recursive and other authoritative name servers. Both types of service can suffer degraded performance as an effect. This is triggered by random subdomains in the NSDNAME in NS records. PowerDNS Recursor 4.1.16, 4.2.2 and 4.3.1 contain a mitigation to limit the impact of this DNS protocol issue.

MaxQueryDuration not honoured in Samba AD DC LDAP

Red Hat CloudForms 3 Management Engine (CFME) allows remote authenticated users to cause a denial of service (resource consumption) via vectors involving calls to the .to_sym rails function and lack of garbage collection of inserted symbols.

OpenStack Dashboard (Horizon) before 2014.1.3 and 2014.2.x before 2014.2.1 does not properly handle session records when using a db or memcached session engine, which allows remote attackers to cause a denial of service via a large number of requests to the login page.

An incomplete fix for CVE-2020-12662 was shipped for Unbound in Red Hat Enterprise Linux 7, as part of erratum RHSA-2020:2414. Vulnerable versions of Unbound could still amplify an incoming query into a large number of queries directed to a target, even with a lower amplification ratio compared to versions of Unbound that shipped before the mentioned erratum. This issue is about the incomplete fix for CVE-2020-12662, and it does not affect upstream versions of Unbound.