CVE-2024-28176: 
JavaScript vulnerability analysis and mitigation

A vulnerability has been identified in the JSON Web Encryption (JWE) decryption interfaces of the jose JavaScript module, specifically related to the support for decompressing plaintext after its decryption. The vulnerability (CVE-2024-28176) was discovered in versions ≤ 4.15.4 and has been patched in versions ^2.0.7 and ^4.15.5 (GitHub Advisory).

The vulnerability allows an adversary to exploit scenarios where the compression ratio becomes exceptionally high during JWE decryption operations. The length of the JWE token, which is determined by the compressed content's size, can fall below application-defined limits, potentially rendering existing application-level mechanisms for preventing resource exhaustion ineffective. The issue has been assigned a CVSS v3.1 base score of 5.3 (Moderate) with vector AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L (GitHub Advisory).

Under certain conditions, it is possible for an attacker to cause the user's environment to consume unreasonable amounts of CPU time or memory during JWE Decryption operations. The impact is limited to Node.js users utilizing the JWE decryption APIs to decrypt JWEs from untrusted sources (GitHub Advisory).

The vulnerability is exploitable when processing JWE tokens from untrusted sources in Node.js environments. Users are not affected if they use jose version v5.x (where JWE Compression is not supported), run in environments other than Node.js, do not use JWE decryption APIs, or only accept JWEs from trusted sources (GitHub Advisory).

The vulnerability has been patched in versions v2.0.7 and v4.15.5, which limit the decompression routine to only allow decompressing up to 250 kB of plaintext. For users who cannot upgrade, they can detect and reject compressed JWE tokens by checking the token's protected header. Additionally, as per RFC 8725, compression of data SHOULD NOT be done before encryption, as compressed data often reveals information about the plaintext (GitHub Advisory).