Petr Šimeček

The vulnerability relates to improper validation of PBMAC1 parameters within PKCS#12 files. Specifically, the PBKDF2 salt and keylength parameters are used without sufficient validation during MAC verification. If the `keylength` value exceeds the size of a fixed stack buffer (64 bytes), a stack-based buffer overflow can occur. Additionally, if the `salt` parameter is not an OCTET STRING type, it can lead to an invalid or NULL pointer dereference. Exploitation requires processing a maliciously crafted PKCS#12 file. This can result in a denial of service (DoS) due to application crashes, and potentially enable code execution depending on platform mitigations. The FIPS modules in versions 3.6, 3.5, and 3.4 are not affected, as PKCS#12 processing falls outside the FIPS module boundary. The vulnerability is triggered when verifying a PKCS#12 file that uses PBMAC1 for the MAC. Attackers can deliver a malicious .p12/.pfx file to systems that import or validate PKCS#12 files from external sources.

A heap-based out-of-bounds write can occur when writing large, newline-free data into a BIO chain utilizing the line-buffering filter, particularly when the subsequent BIO performs short writes. This memory corruption can lead to a denial of service. The line-buffering BIO filter (BIO f linebuffer) is not typically used in default TLS/SSL configurations. The issue is assessed as low severity due to the unlikely circumstances of attacker control and the filter's limited use with attacker-controlled data. The FIPS modules in versions 3.0, 3.3, 3.4, 3.5, and 3.6 are not affected as the BIO implementation is outside the FIPS module boundary.