How severe is CVE-2013-0757?

CVE-2013-0757 has a CVSS 2.0 base score of 9.3, rated critical severity.

Is CVE-2013-0757 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 61% (99th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2013-0757?

CVE-2013-0757 primarily affects Mozilla Firefox. In total, 18 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2013-0757?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2013-0757 published?

CVE-2013-0757 was published on 2013-01-13 and last updated on 2026-06-16.

CVE-2013-0757

CVE-2013-0757 is a critical-severity vulnerability in Mozilla Firefox with a CVSS 2.0 base score of 9.3. Its EPSS exploit-prediction score of 61% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-20.

Key facts

Severity: Critical (CVSS 2.0 base score 9.3)
EPSS exploit prediction: 61% (99th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Mozilla Firefox
Published: 2013-01-13
Last modified: 2026-06-16

Description

The Chrome Object Wrapper (COW) implementation in Mozilla Firefox before 18.0, Firefox ESR 17.x before 17.0.2, Thunderbird before 17.0.2, Thunderbird ESR 17.x before 17.0.2, and SeaMonkey before 2.15 does not prevent modifications to the prototype of an object, which allows remote attackers to execute arbitrary JavaScript code with chrome privileges by referencing Object.prototype.__proto__ in a crafted HTML document.

Frequently asked questions

What is CVE-2013-0757?: The Chrome Object Wrapper (COW) implementation in Mozilla Firefox before 18.0, Firefox ESR 17.x before 17.0.2, Thunderbird before 17.0.2, Thunderbird ESR 17.x before 17.0.2, and SeaMonkey before 2.15 does not prevent modifications to the prototype of an object, which allows remote attackers to execute arbitrary JavaScript code with chrome privileges by referencing Object.prototype.__proto__ in a crafted HTML document.
How severe is CVE-2013-0757?: CVE-2013-0757 has a CVSS 2.0 base score of 9.3, rated critical severity.
Is CVE-2013-0757 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 61% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2013-0757?: CVE-2013-0757 primarily affects Mozilla Firefox. In total, 18 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2013-0757?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2013-0757 published?: CVE-2013-0757 was published on 2013-01-13 and last updated on 2026-06-16.

References

Affected products (18)

cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:seamonkey:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:thunderbird_esr:*:*:*:*:*:*:*:*
cpe:2.3:o:opensuse:opensuse:11.4:*:*:*:*:*:*:*
cpe:2.3:o:opensuse:opensuse:12.1:*:*:*:*:*:*:*
cpe:2.3:o:opensuse:opensuse:12.2:*:*:*:*:*:*:*
cpe:2.3:o:suse:linux_enterprise_desktop:10:sp4:*:*:*:*:*:*
cpe:2.3:o:suse:linux_enterprise_desktop:11:sp2:*:*:*:*:*:*
cpe:2.3:o:suse:linux_enterprise_server:10:sp4:*:*:*:*:*:*
cpe:2.3:o:suse:linux_enterprise_server:11:sp2:*:*:*:-:*:*
cpe:2.3:o:suse:linux_enterprise_server:11:sp2:*:*:*:vmware:*:*
cpe:2.3:o:suse:linux_enterprise_software_development_kit:10:sp4:*:*:*:*:*:*
cpe:2.3:o:suse:linux_enterprise_software_development_kit:11:sp2:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:10.04:*:*:*:-:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:11.10:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:esm:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:12.10:*:*:*:*:*:*:*

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