CVEvulnerability
CVE-2020-26961
6.5 MEDIUM
Official page ↗
- Status
- Modified
- Published
- 2020-12-09
- Last modified
- 2026-06-17
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 6.5 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
- CVSS 2.0 ([email protected])
- 4.3 MEDIUM — AV:N/AC:M/Au:N/C:N/I:P/A:N
Description
When DNS over HTTPS is in use, it intentionally filters RFC1918 and related IP ranges from the responses as these do not make sense coming from a DoH resolver. However when an IPv4 address was mapped through IPv6, these addresses were erroneously let through, leading to a potential DNS Rebinding attack. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.
Affected configurations
• mozilla firefox (< 83.0)
• mozilla firefox esr (< 78.5)
• mozilla thunderbird (< 78.5)
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1672528 Issue Tracking, Permissions Required, Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2020-50/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2020-51/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2020-52/ Vendor Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1672528 Issue Tracking, Permissions Required, Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2020-50/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2020-51/ Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2020-52/ Vendor Advisory