SARA / Free Tools / CVE / CVE-2023-6857

CVE-2023-6857 — When resolving a symlink, a race may occur where the buffer passed to `readlink`

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

CVSS
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EPSS
0.19% (top 59.50%)
CWE
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Published
2023-12-19T13:38:37.621Z
Last modified
2025-02-13T17:26:34.338Z
CVSS vector
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01What is this vulnerability?

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.

02Affected products

VendorProductVersions
MozillaFirefox ESRunspecified
MozillaThunderbirdunspecified
MozillaFirefoxunspecified

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

09References

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