Integer underflow in wolfSSL packet sniffer <= 5.8.4 allows an attacker to cause a buffer overflow in the AEAD decryption path by injecting a TLS record shorter than the explicit IV plus authentication tag into traffic inspected by ssl_DecodePacket. The underflow wraps a 16-bit length to a large value that is passed to AEAD decryption routines, causing heap buffer overflow and a crash. An unauthenticated attacker can trigger this remotely via malformed TLS Application Data records.

A 1-byte stack buffer over-read was identified in the MatchDomainName function (src/internal.c) during wildcard hostname validation when the LEFT_MOST_WILDCARD_ONLY flag is active. If a wildcard * exhausts the entire hostname string, the function reads one byte past the buffer without a bounds check, which could cause a crash.

An integer underflow issue exists in wolfSSL when parsing the Subject Alternative Name (SAN) extension of X.509 certificates. A malformed certificate can specify an entry length larger than the enclosing sequence, causing the internal length counter to wrap during parsing. This results in incorrect handling of certificate data. The issue is limited to configurations using the original ASN.1 parsing implementation which is off by default.

Integer Underflow Leads to Out-of-Bounds Access in XChaCha20-Poly1305 Decrypt. This issue is hit specifically with a call to the function wc_XChaCha20Poly1305_Decrypt() which is not used with TLS connections, only from direct calls from an application.

A vulnerability in Internet Key Exchange version 2 (IKEv2) processing of Cisco Secure Client Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) of Cisco Secure Client. This vulnerability is due to an integer underflow condition. An attacker could exploit this vulnerability by sending a crafted IKEv2 packet to an affected system. A successful exploit could allow the attacker to cause Cisco Secure Client Software to crash, resulting in a DoS condition on the client software. Note: Cisco Secure Client Software releases 4.10 and earlier were known as Cisco AnyConnect Secure Mobility Client.

Microsoft Message Queuing (MSMQ) Denial of Service Vulnerability