Vulnerability identifier: #VU84559

Vulnerability risk: Low

CVSSv3.1: 2.2 [CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2023-6857

CWE-ID: CWE-124

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Mozilla Firefox
Client/Desktop applications / Web browsers
Firefox ESR
Client/Desktop applications / Web browsers
Firefox for Android
Mobile applications / Apps for mobile phones

Vendor: Mozilla

Description

The vulnerability allows a local user to gain access to sensitive information.

The vulnerability exists due to an error when handling symbolic links. A local user can trigger a race when the browser resolves a symbolic link, where the buffer passed to readlink may actually be smaller than necessary. A local user can gain access to potentially sensitive information.

The vulnerability affects Unix based operating systems only (e.g. Android, Linux, MacOS).

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Mozilla Firefox: 100.0 - 120.0.1

Firefox ESR: 115.0 - 115.5.0, 102.0 - 102.15.1

Firefox for Android: 66.0.4 - 120.1.1

---

External links
http://www.mozilla.org/en-US/security/advisories/mfsa2023-54/
http://www.mozilla.org/en-US/security/advisories/mfsa2023-56/

---

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.