CVE-2023-31147: Insufficient randomness in generation of DNS query IDs in c-ares
First published: Wed May 24 2023(Updated: )
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.
Credit: security-advisories@github.com security-advisories@github.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| C-ares Project C-ares | <1.19.1 | |
| Fedoraproject Fedora | =37 | |
| Fedoraproject Fedora | =38 |
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Reference Links
- https://github.com/c-ares/c-ares/releases/tag/cares-1_19_1
- https://github.com/c-ares/c-ares/security/advisories/GHSA-8r8p-23f3-64c2
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/B5Z5XFNXTNPTCBBVXFDNZQVLLIE6VRBY/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UBFWILTA33LOSV23P44FGTQQIDRJHIY7/
- https://security.gentoo.org/glsa/202310-09
- https://access.redhat.com/security/cve/CVE-2023-31147
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2209542
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2209543
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2209539
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2209544
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2209545
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2209546
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2209540
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2209541
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2209547
- https://access.redhat.com/errata/RHSA-2023:3577
- https://access.redhat.com/errata/RHSA-2023:3586
- https://access.redhat.com/errata/RHSA-2023:4036
- https://access.redhat.com/errata/RHSA-2023:4039
- https://access.redhat.com/errata/RHSA-2023:4035
- https://access.redhat.com/errata/RHSA-2023:4034
- https://access.redhat.com/errata/RHSA-2023:4033
- https://access.redhat.com/errata/RHSA-2023:6635
- https://bugzilla.redhat.com/show_bug.cgi?id=2209501
Frequently Asked Questions
What is CVE-2023-31147?
CVE-2023-31147 is a vulnerability in the c-ares library that allows for the generation of predictable random numbers for DNS query IDs.
How does CVE-2023-31147 affect c-ares?
CVE-2023-31147 affects c-ares versions up to and including 1.19.1.
What is the severity of CVE-2023-31147?
The severity of CVE-2023-31147 is medium with a CVSS score of 6.5.
How can I fix CVE-2023-31147?
To fix CVE-2023-31147, you should upgrade to a version of c-ares that is not affected by this vulnerability.
Where can I find more information about CVE-2023-31147?
You can find more information about CVE-2023-31147 at the following references: [Access Red Hat](https://access.redhat.com/security/cve/CVE-2023-31147), [GitHub Security Advisory](https://github.com/c-ares/c-ares/security/advisories/GHSA-8r8p-23f3-64c2), [Bugzilla Red Hat](https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2209542).
- collector/nvd-latest
- vendor/c-ares project
- vendor/c-ares
- vendor/fedoraproject
- vendor/fedora
- product/c-ares
- canonical/c-ares project c-ares
- product/fedora
- canonical/fedoraproject fedora
- collector/nvd-index
- collector/nvd-api
- agent/author
- agent/type
- agent/softwarecombine
- agent/first-publish-date
- agent/references
- agent/weakness
- agent/description
- collector/redhat-bugzilla
- source/Red Hat
- alias/CVE-2023-31147
- collector/mitre-cve
- source/MITRE
- agent/last-modified-date
- agent/title
- agent/severity
- agent/tags
- agent/event
- version/fedoraproject fedora/37
- version/fedoraproject fedora/38