Vulnerabilities > CVE-2023-31147

047910
CVSS 6.5 - MEDIUM
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
LOW
Integrity impact
LOW
Availability impact
NONE
network
low complexity
c-ares-project
fedoraproject

Summary

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.