CVE-2023-31147
Published: 25 May 2023
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.
Notes
| Author | Note |
|---|---|
| mdeslaur | urandom is always available on Ubuntu and is detected during build |
Priority
Status
| Package | Release | Status |
|---|---|---|
|
c-ares Launchpad, Ubuntu, Debian |
bionic |
Not vulnerable
|
| focal |
Not vulnerable
|
|
| jammy |
Not vulnerable
|
|
| kinetic |
Not vulnerable
|
|
| lunar |
Not vulnerable
|
|
| trusty |
Ignored
(end of standard support)
|
|
| upstream |
Released
(1.19.1)
|
|
| xenial |
Not vulnerable
|
|
|
Patches: upstream: https://github.com/c-ares/c-ares/commit/823df3b989e59465d17b0a2eb1239a5fc048b4e5 |
||
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 6.5 |
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | Low |
| Integrity impact | Low |
| Availability impact | None |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N |