CVE-2019-11757

Description

When following the value's prototype chain, it was possible to retain a reference to a locale, delete it, and subsequently reference it. This resulted in a use-after-free and a potentially exploitable crash. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.

CVSS Metrics

• v3.1•HIGH•Score: 8.8CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
• v2.0•MEDIUM•Score: 6.8AV:N/AC:M/Au:N/C:P/I:P/A:P

EPSS Trends

Current EPSS score: 1.34%• Percentile: 70%

Techniques & Countermeasures

• CWE-416•Use After Free

  The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected Systems

• canonical•ubuntu_linux

  16.04

• debian•firefox-esr

  < 68.2.0esr-1 | < 68.2.0esr-1 | < 68.2.0esr-1 | < 68.2.0esr-1

• debian•thunderbird

  < 1:68.2.1-1 | < 1:68.2.1-1 | < 1:68.2.1-1 | < 1:68.2.1-1

• mozilla•firefox

  < 70 | < 70.0

• mozilla•firefox_esr

  < 68.2

• mozilla•thunderbird

  < 68.2

References (7)

• https://www.mozilla.org/security/advisories/mfsa2019-35/
• https://www.mozilla.org/security/advisories/mfsa2019-33/
• https://www.mozilla.org/security/advisories/mfsa2019-34/
• https://bugzilla.mozilla.org/show_bug.cgi?id=1577107
• https://security.gentoo.org/glsa/202003-10
• https://usn.ubuntu.com/4335-1/
• https://security-tracker.debian.org/tracker/CVE-2019-11757