Summary
Package updates are available for Amazon Linux 2 that fix the following vulnerabilities: CVE-2023-31147: Insufficient randomness in generation of DNS query IDs 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.
Fixed packages 3
| Release | Package | Fixed in |
|---|---|---|
| Amazon Linux · 2 | c-ares | 0:1.19.1-1.amzn2.0.1 |
| Amazon Linux · 2 | c-ares-debuginfo | 0:1.19.1-1.amzn2.0.1 |
| Amazon Linux · 2 | c-ares-devel | 0:1.19.1-1.amzn2.0.1 |
Vulnerabilities 1
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Medium 5.9
Insufficient randomness in generation of DNS query IDs in c-ares
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 outp…
References
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web
https://alas.aws.amazon.com/cve/html/CVE-2023-31147.html