SB2025052231 - Multiple vulnerabilities in Mozilla Thunderbird

Description

This security bulletin contains information about 2 secuirty vulnerabilities.

1) Out-of-bounds write (CVE-ID: CVE-2025-4920)

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a boundary error when processing JavaScript "Promise" object. A remote attacker can trick the victim into visiting a specially crafted website, trigger an out-of-bounds write and execute arbitrary code on the target system.

2) Out-of-bounds write (CVE-ID: CVE-2025-4921)

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a boundary error when manipulating a JavaScript object by confusing array index sizes. A remote attacker can trick the victim into visiting a specially crafted website, trigger an out-of-bounds write and execute arbitrary code on the target system.

Remediation

Install update from vendor's website.

References

• https://www.mozilla.org/en-US/security/advisories/mfsa2025-40/"
• https://www.mozilla.org/en-US/security/advisories/mfsa2025-40/</a></p><p>
• https://www.mozilla.org/en-US/security/advisories/mfsa2025-41/</p><p><br></p>