CVE-2020-15655
CVE-2020-15655 is a medium-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.
Key facts
- Severity: Medium (CVSS 3.x base score 6.5)
- CVSS v2: 4.3
- EPSS exploit prediction: 2% (72nd percentile)
- Actively exploited: Not listed in CISA KEV
- Affected product: Mozilla Firefox
- Published:
- Last modified:
Description
A redirected HTTP request which is observed or modified through a web extension could bypass existing CORS checks, leading to potential disclosure of cross-origin information. This vulnerability affects Firefox ESR < 78.1, Firefox < 79, and Thunderbird < 78.1.
Frequently asked questions
- What is CVE-2020-15655?
- A redirected HTTP request which is observed or modified through a web extension could bypass existing CORS checks, leading to potential disclosure of cross-origin information. This vulnerability affects Firefox ESR < 78.1, Firefox < 79, and Thunderbird < 78.1.
- How severe is CVE-2020-15655?
- CVE-2020-15655 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.
- Is CVE-2020-15655 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2020-15655?
- CVE-2020-15655 primarily affects Mozilla Firefox. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2020-15655?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- When was CVE-2020-15655 published?
- CVE-2020-15655 was published on 2020-08-10 and last updated on 2026-06-17.
References
- http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00025.html
- https://bugzilla.mozilla.org/show_bug.cgi?id=1645204
- https://usn.ubuntu.com/4443-1/
- https://www.mozilla.org/security/advisories/mfsa2020-30/
- https://www.mozilla.org/security/advisories/mfsa2020-32/
- https://www.mozilla.org/security/advisories/mfsa2020-33/
Affected products (7)
- cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
- cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*
- cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
- cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
- cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*
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