CVE-2020-26974 — Out-of-bounds Write in Mozilla Firefox

CWE-787 — Out-of-bounds WriteCWE-416 — Use After Free12 documents8 sources
Severity
8.8HIGHNVD
OSV6.5
EPSS
0.8%
top 26.61%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
3
Mozilla FirefoxMozilla Firefox ESRMozilla Thunderbird
Timeline
PublishedJan 7
Latest updateMay 24

Description

When flex-basis was used on a table wrapper, a StyleGenericFlexBasis object could have been incorrectly cast to the wrong type. This resulted in a heap user-after-free, memory corruption, and a potentially exploitable crash. This vulnerability affects Firefox < 84, Thunderbird < 78.6, and Firefox ESR < 78.6.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HExploitability: 2.8 | Impact: 5.9

Affected Packages8 packages

▶CVEListV5mozilla/firefoxunspecified — 84
▶NVDmozilla/firefox< 84.0
▶CVEListV5mozilla/firefox_esrunspecified — 78.6
▶NVDmozilla/firefox_esr< 78.6.0
▶Ubuntumozilla/firefox< 84.0+build3-0ubuntu0.16.04.1+2

🔴Vulnerability Details

4
GHSA
GHSA-gr4h-9jxj-93vm: When flex-basis was used on a table wrapper, a StyleGenericFlexBasis object could have been incorrectly cast to the wrong type↗2022-05-24
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CVEList
CVE-2020-26974: When flex-basis was used on a table wrapper, a StyleGenericFlexBasis object could have been incorrectly cast to the wrong type↗2021-01-07
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OSV
CVE-2020-26974: When flex-basis was used on a table wrapper, a StyleGenericFlexBasis object could have been incorrectly cast to the wrong type↗2021-01-07
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OSV
firefox vulnerabilities↗2020-12-15
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📋Vendor Advisories

7
Ubuntu
Thunderbird vulnerabilities↗2021-01-20
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Red Hat
Mozilla: Incorrect cast of StyleGenericFlexBasis resulted in a heap use-after-free↗2020-12-15
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Ubuntu
Firefox vulnerabilities↗2020-12-15
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Debian
CVE-2020-26974: firefox - When flex-basis was used on a table wrapper, a StyleGenericFlexBasis object coul...↗2020
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Mozilla
Mozilla Foundation Security Advisory 2020-55: CVE-2020-26974↗
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CVE-2020-26974 — Out-of-bounds Write in Mozilla Firefox | cvebase