Home/CVE/When resolving a symlink, a race may occur where the buffer passed to `readlink` may actually be smaller than necessary.
CVE

CVE-2023-6857

When resolving a symlink, a race may occur where the buffer passed to `readlink` may actually be smaller than necessary.

When resolving a symlink, a race may occur where the buffer passed to readlink may actually be smaller than necessary. This bug only affects Firefox on Unix-based operating systems (Android, Linux, MacOS). Windows is unaffected. This vulnerability affects Firefox ESR < 115.6, Thunderbird < 115.6, and Firefox < 121.

MEDIUM · CVSS 5.3 EPSS 0.00227
Monitor
  • No active-exploitation, high-EPSS, or public-exploit signals - routine patching cadence
Sigma rules9 YARA rules0
⬡

Weakness Classification

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
▤

Affected Products & Versions

4
mozilla firefox< 121.0
mozilla firefox esr< 115.6
mozilla thunderbird< 115.6
debian linuxall versions
◈

Sigma Hunt Rules

9
Exact rules name this CVE ID. Product rules name an affected product in their title. Related rules cover techniques used by actors who exploited this CVE. Showing the most relevant matches; the complete related set is on the full drill-down.
producthighSuspicious Microsoft Office Child Process - MacOS
producthighRemote Access Tool - Renamed MeshAgent Execution - MacOS
producthighBinary Padding - MacOS
productmediumSuspicious Execution via macOS Script Editor
productmediumSystem Information Discovery Via Sysctl - MacOS
productmediumNew File Exclusion Added To Time Machine Via Tmutil - MacOS
▣

Scoring & Timeline

5.3
MEDIUM · CVSS v3.1 · security@mozilla.org
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD19 Dec 2023 · 02:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N
⚑

Vendor Advisories

28
suse-csafopenSUSE-SU-2024:14572-1
suse-csafopenSUSE-SU-2024:13519-1
suse-csafopenSUSE-SU-2024:13531-1
suse-csafSUSE-SU-2024:0044-1
usnUSN-6563-1
🔗

References & Sources

9
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://bugzilla.mozilla.org/show_bug.cgi?id=1796023Issue TrackingPermissions Required
https://lists.debian.org/debian-lts-announce/2023/12/msg00020.htmlMailing ListThird Party Advisory
https://lists.debian.org/debian-lts-announce/2023/12/msg00021.htmlMailing ListThird Party Advisory
https://security.gentoo.org/glsa/202401-10Third Party Advisory
https://www.debian.org/security/2023/dsa-5581Third Party Advisory
https://www.debian.org/security/2023/dsa-5582Third Party Advisory
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