When encrypting with a block cipher, if a call to NSC_EncryptUpdate was made with data smaller than the block size, a small out of bounds write could occur. This could have caused heap corruption and a potentially exploitable crash. This vulnerability affects Thunderbird < 68.3, Firefox ESR < 68.3, and Firefox < 71.
http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00000.html
http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00001.html
http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00006.html
https://access.redhat.com/errata/RHSA-2020:0243
https://access.redhat.com/errata/RHSA-2020:0466
https://bugzilla.mozilla.org/show_bug.cgi?id=1586176
https://cert-portal.siemens.com/productcert/pdf/ssa-379803.pdf
https://lists.debian.org/debian-lts-announce/2020/09/msg00029.html
https://security.gentoo.org/glsa/202003-02
https://security.gentoo.org/glsa/202003-10
https://security.gentoo.org/glsa/202003-37
https://us-cert.cisa.gov/ics/advisories/icsa-21-040-04
https://usn.ubuntu.com/4241-1/
https://usn.ubuntu.com/4335-1/
https://www.mozilla.org/security/advisories/mfsa2019-36/
Source: MITRE
Published: 2020-01-08
Updated: 2021-02-19
Type: CWE-787
Base Score: 6.8
Vector: AV:N/AC:M/Au:N/C:P/I:P/A:P
Impact Score: 6.4
Exploitability Score: 8.6
Severity: MEDIUM
Base Score: 8.8
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Impact Score: 5.9
Exploitability Score: 2.8
Severity: HIGH