CVE-2022-29242: 
Linux Debian vulnerability analysis and mitigation

GOST engine, a reference implementation of Russian GOST crypto algorithms for OpenSSL, was found to contain a buffer overflow vulnerability (CVE-2022-29242) discovered in May 2022. The vulnerability specifically affects TLS clients using GOST engine when the ciphersuite TLS_GOSTR341112_256_WITH_KUZNYECHIK_CTR_OMAC is agreed upon and the server uses 512-bit GOST secret keys (GitHub Advisory).

The vulnerability stems from improper buffer size handling when creating key transport blobs. According to RFC 9189 section 4.2.4, there are two variants of GOST key wrap into blob, both requiring the same approach for checking passed values. While OpenSSL passes a sufficiently large buffer for the variant described in section 4.2.4.2, it fails to provide an adequate buffer for section 4.2.4.1, leading to a potential buffer overflow condition. The vulnerability has been assigned a CVSS v3.1 score of 7.5 HIGH (NVD).

When exploited, this vulnerability could lead to buffer overflow in the client when the server has 512-bit keys and a KUZNYECHIK-based ciphersuite is in use. This could potentially result in memory corruption and possible code execution (GitHub Advisory).

The vulnerability has been patched in GOST engine version 3.0.1. Users are advised to update to this version. As a temporary workaround, users can disable the ciphersuite TLS_GOSTR341112_256_WITH_KUZNYECHIK_CTR_OMAC (GitHub Advisory).