Risk | High |
Patch available | YES |
Number of vulnerabilities | 2 |
CVE-ID | CVE-2025-4918 CVE-2025-4920 CVE-2025-4919 CVE-2025-4921 |
CWE-ID | CWE-787 |
Exploitation vector | Network |
Public exploit | N/A |
Vulnerable software |
Mozilla Firefox Client/Desktop applications / Web browsers Firefox ESR Client/Desktop applications / Web browsers |
Vendor | Mozilla |
Security Bulletin
This security bulletin contains information about 2 vulnerabilities.
EUVDB-ID: #VU109400
Risk: High
CVSSv4.0: 6.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]
CVE-ID: CVE-2025-4918,CVE-2025-4920
CWE-ID:
CWE-787 - Out-of-bounds write
Exploit availability: No
DescriptionThe 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.
MitigationInstall updates from vendor's website.
Vulnerable software versionsMozilla Firefox: 110.0 - 138.0.3
Firefox ESR: 102.0 - 128.10.0
CPE2.3https://bugzilla.mozilla.org/show_bug.cgi?id=1966612
https://www.mozilla.org/security/advisories/mfsa2025-36/
https://www.mozilla.org/security/advisories/mfsa2025-37/
https://www.mozilla.org/en-US/security/advisories/mfsa2025-38/
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
How the attacker can exploit this vulnerability?
The attacker would have to trick the victim to visit a specially crafted website.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
EUVDB-ID: #VU109401
Risk: High
CVSSv4.0: 6.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]
CVE-ID: CVE-2025-4919,CVE-2025-4921
CWE-ID:
CWE-787 - Out-of-bounds write
Exploit availability: No
DescriptionThe 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.
MitigationInstall updates from vendor's website.
Vulnerable software versionsMozilla Firefox: 110.0 - 138.0.3
Firefox ESR: 102.0 - 128.10.0
CPE2.3https://bugzilla.mozilla.org/show_bug.cgi?id=1966614
https://www.mozilla.org/security/advisories/mfsa2025-36/
https://www.mozilla.org/security/advisories/mfsa2025-37/
https://www.mozilla.org/en-US/security/advisories/mfsa2025-38/
https://www.zerodayinitiative.com/advisories/ZDI-25-292/
https://www.zerodayinitiative.com/advisories/ZDI-25-291/
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
How the attacker can exploit this vulnerability?
The attacker would have to trick the victim to visit a specially crafted website.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.