CVE-2023-6857

Mozilla: Symlinks may resolve to smaller than expected buffers

Severity Score

5.3

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

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.

Al resolver un enlace simbólico, puede ocurrir una ejecución en la que el búfer pase a "readlink" en realidad puede ser más pequeño de lo necesario. *Este error sólo afecta a Firefox en sistemas operativos basados en Unix (Android, Linux, MacOS). Windows no se ve afectado.* Esta vulnerabilidad afecta a Firefox ESR < 115.6, Thunderbird < 115.6 y Firefox < 121.

The Mozilla Foundation Security Advisory describes this flaw as:

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.*

*Credits: Jed Davis

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

None

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2023-12-15 CVE Reserved
2023-12-19 CVE Published
2024-08-02 CVE Updated
2024-11-18 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CWE-363: Race Condition Enabling Link Following

CAPEC

References (10)

URL	Tag	Source
https://lists.debian.org/debian-lts-announce/2023/12/msg00020.html	Mailing List
https://lists.debian.org/debian-lts-announce/2023/12/msg00021.html	Mailing List
https://security.gentoo.org/glsa/202401-10	Third Party Advisory
https://www.debian.org/security/2023/dsa-5581	Third Party Advisory
https://www.debian.org/security/2023/dsa-5582	Third Party Advisory

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://www.mozilla.org/security/advisories/mfsa2023-54	2024-02-02
https://www.mozilla.org/security/advisories/mfsa2023-55	2024-02-02
https://www.mozilla.org/security/advisories/mfsa2023-56	2024-02-02
https://access.redhat.com/security/cve/CVE-2023-6857	2024-01-02
https://bugzilla.redhat.com/show_bug.cgi?id=2255362	2024-01-02

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Mozilla Search vendor "Mozilla"	Firefox Search vendor "Mozilla" for product "Firefox"	< 121.0 Search vendor "Mozilla" for product "Firefox" and version " < 121.0"	-	Affected	in	Apple Search vendor "Apple"	Macos Search vendor "Apple" for product "Macos"	-	-	Safe
Mozilla Search vendor "Mozilla"	Firefox Search vendor "Mozilla" for product "Firefox"	< 121.0 Search vendor "Mozilla" for product "Firefox" and version " < 121.0"	-	Affected	in	Google Search vendor "Google"	Android Search vendor "Google" for product "Android"	-	-	Safe
Mozilla Search vendor "Mozilla"	Firefox Search vendor "Mozilla" for product "Firefox"	< 121.0 Search vendor "Mozilla" for product "Firefox" and version " < 121.0"	-	Affected	in	Linux Search vendor "Linux"	Linux Kernel Search vendor "Linux" for product "Linux Kernel"	-	-	Safe
Mozilla Search vendor "Mozilla"	Firefox Esr Search vendor "Mozilla" for product "Firefox Esr"	< 115.6 Search vendor "Mozilla" for product "Firefox Esr" and version " < 115.6"	-	Affected	in	Apple Search vendor "Apple"	Macos Search vendor "Apple" for product "Macos"	-	-	Safe
Mozilla Search vendor "Mozilla"	Firefox Esr Search vendor "Mozilla" for product "Firefox Esr"	< 115.6 Search vendor "Mozilla" for product "Firefox Esr" and version " < 115.6"	-	Affected	in	Google Search vendor "Google"	Android Search vendor "Google" for product "Android"	-	-	Safe
Mozilla Search vendor "Mozilla"	Firefox Esr Search vendor "Mozilla" for product "Firefox Esr"	< 115.6 Search vendor "Mozilla" for product "Firefox Esr" and version " < 115.6"	-	Affected	in	Linux Search vendor "Linux"	Linux Kernel Search vendor "Linux" for product "Linux Kernel"	-	-	Safe
Mozilla Search vendor "Mozilla"	Thunderbird Search vendor "Mozilla" for product "Thunderbird"	< 115.6 Search vendor "Mozilla" for product "Thunderbird" and version " < 115.6"	-	Affected	in	Apple Search vendor "Apple"	Macos Search vendor "Apple" for product "Macos"	-	-	Safe
Mozilla Search vendor "Mozilla"	Thunderbird Search vendor "Mozilla" for product "Thunderbird"	< 115.6 Search vendor "Mozilla" for product "Thunderbird" and version " < 115.6"	-	Affected	in	Google Search vendor "Google"	Android Search vendor "Google" for product "Android"	-	-	Safe
Mozilla Search vendor "Mozilla"	Thunderbird Search vendor "Mozilla" for product "Thunderbird"	< 115.6 Search vendor "Mozilla" for product "Thunderbird" and version " < 115.6"	-	Affected	in	Linux Search vendor "Linux"	Linux Kernel Search vendor "Linux" for product "Linux Kernel"	-	-	Safe
Debian Search vendor "Debian"		Debian Linux Search vendor "Debian" for product "Debian Linux"				10.0 Search vendor "Debian" for product "Debian Linux" and version "10.0"		-		Affected
Debian Search vendor "Debian"		Debian Linux Search vendor "Debian" for product "Debian Linux"				11.0 Search vendor "Debian" for product "Debian Linux" and version "11.0"		-		Affected
Debian Search vendor "Debian"		Debian Linux Search vendor "Debian" for product "Debian Linux"				12.0 Search vendor "Debian" for product "Debian Linux" and version "12.0"		-		Affected