When an extension with the proxy permission registered to receive <all_urls>, the proxy.onRequest callback was not triggered for view-source URLs. While web content cannot navigate to such URLs, a user opening View Source could have inadvertently leaked their IP address. This vulnerability affects Firefox < 84, Thunderbird < 78.6, and Firefox ESR < 78.6.
https://bugzilla.mozilla.org/show_bug.cgi?id=1657916
https://www.mozilla.org/security/advisories/mfsa2020-54/
Source: MITRE
Published: 2021-01-07
Updated: 2021-01-12
Type: NVD-CWE-noinfo
Base Score: 4.3
Vector: AV:N/AC:M/Au:N/C:P/I:N/A:N
Impact Score: 2.9
Exploitability Score: 8.6
Severity: MEDIUM
Base Score: 4.3
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
Impact Score: 1.4
Exploitability Score: 2.8
Severity: MEDIUM