CVE-2020-14354
Description
A possible use-after-free and double-free in c-ares lib version 1.16.0 if ares_destroy() is called prior to ares_getaddrinfo() completing. This flaw possibly allows an attacker to crash the service that uses c-ares lib. The highest threat from this vulnerability is to this service availability.
Statement
This flaw is rated as a having Moderate impact, because it can happen only during close of the service (or when handling ARES_ECONNREFUSED). The Red Hat Enterprise Linux not affected (all versions), because the version of c-ares being used is 1.13.0, and the bug introduced in 1.16.0 (and then fixed in 1.16.1).
Mitigation
If calling wait_ares(channel) before ares_destroy() in the service that uses c-ares, then this should prevent this bug.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.9 | 3.3 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | Low | None | N/A |
| Integrity Impact | Low | None | N/A |
| Availability Impact | Low | Low | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
Understanding the Weakness (CWE)
Availability,Integrity
Technical Impact: DoS: Crash, Exit, or Restart
Acknowledgements
Red Hat would like to thank Jann Horn (Google Project Zero) for reporting this issue.
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