c-ares is an asynchronous resolver library. When /dev/urandom or RtlGenRandom() are unavailable, c-ares uses rand() to generate random numbers used for DNS query ids. This is not a CSPRNG, and it is also not seeded by srand() so will generate predictable output. Input from the random number generator is fed into a non-compilant RC4 implementation and may not be as strong as the original RC4 implementation. No attempt is made to look for modern OS-provided CSPRNGs like arc4random() that is widely available. This issue has been fixed in version 1.19.1.
No PoCs from references.
- https://github.com/NVIDIA-AI-Blueprints/vulnerability-analysis
- https://github.com/Swapnilalone901/vna
- https://github.com/fkie-cad/nvd-json-data-feeds
- https://github.com/katherineh123/temp-vuln-analysis