CVE-2020-36177: 
NixOS vulnerability analysis and mitigation

RsaPad_PSS in wolfcrypt/src/rsa.c in wolfSSL before 4.6.0 has an out-of-bounds write for certain relationships between key size and digest size (NVD). The vulnerability was discovered and disclosed in January 2021.

The vulnerability occurs in the RsaPad_PSS function when the key is small relative to the digest (e.g., 1024-bit key, 64-byte hash, 61-byte salt length), where the internal message to hash is larger than the output size. This can lead to an out-of-bounds write condition (GitHub Commit). The vulnerability has been assigned a CVSS v3.1 base score of 9.8 CRITICAL (NVD).

The vulnerability could allow remote attackers to execute arbitrary code or cause a denial of service through memory corruption. Given the CVSS score of 9.8, this indicates critical severity with potential for complete compromise of affected systems (NVD).

The vulnerability has been classified as having low attack complexity and requiring no privileges or user interaction to exploit. The attack can be launched remotely (NVD).

The vulnerability was fixed in wolfSSL version 4.6.0. The fix involves allocating a buffer for the message when the internal message to hash is larger than the output size (GitHub PR). Users should upgrade to wolfSSL version 4.6.0 or later to address this vulnerability.