The version of Firefox installed on the remote macOS or Mac OS X host is prior to 75.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2020-12 advisory.

  - Mozilla developers Tyson Smith, Bob Clary, and Alexandru Michis reported memory safety bugs present in     Firefox 74. Some of these bugs showed evidence of memory corruption and we presume that with enough effort     some of these could have been exploited to run arbitrary code. (CVE-2020-6826)

  - When reading from areas partially or fully outside the source resource with WebGL's     <code>copyTexSubImage</code> method, the specification requires the returned values be zero. Previously,     this memory was uninitialized, leading to potentially sensitive data disclosure. (CVE-2020-6821)

  - On 32-bit builds, an out of bounds write could have occurred when processing an image larger than 4 GB in     <code>GMPDecodeData</code>. It is possible that with enough effort this could have been exploited to run     arbitrary code. (CVE-2020-6822)

  - A malicious extension could have called <code>browser.identity.launchWebAuthFlow</code>, controlling the     redirecturi, and through the Promise returned, obtain the Auth code and gain access to the user's account     at the service provider. (CVE-2020-6823)

  - Initially, a user opens a Private Browsing Window and generates a password for a site, then closes the     Private Browsing Window but leaves Firefox open. Subsequently, if the user had opened a new Private     Browsing Window, revisited the same site, and generated a new password - the generated passwords would     have been identical, rather than independent. (CVE-2020-6824)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Detections

Analytics

Mozilla Firefox < 75.0

critical Nessus Plugin ID 135275

Version 1.4

Version 1.3

Version 1.2

Version 1.4 Nov 19, 2025, 7:37 AM Detection (updated detection logic) Plugin metadata Plugin Feed: 202511190737
Version 1.3 Mar 19, 2024, 2:37 PM CVSSv2 score source (changed from "CVE-2020-6825" to "CVE-2020-6826") Exploit attributes ("Exploit available" set to "False") Plugin Feed: 202403191437
Version 1.2 Mar 19, 2024, 12:36 PM CVSSv2 score source (changed from "CVE-2020-6825" to "CVE-2020-6826") Exploit attributes ("Exploit available" set to "False") Plugin Feed: 202403191236