⚠ Actively exploited
Added to CISA KEV on 2021-11-03. Federal agencies required to patch by 2022-05-03. Required action: Apply updates per vendor instructions..

CVE-2020-6819Race Condition in Mozilla Firefox

Severity
8.1HIGHNVD
OSV8.8OSV6.5
EPSS
0.4%
top 41.56%
CISA KEV
KEV
Added 2021-11-03
Due 2022-05-03
Exploit
Exploited in wild
Active exploitation observed
Timeline
PublishedApr 24
KEV addedNov 3
KEV dueMay 3
Latest updateMay 24
CISA Required Action: Apply updates per vendor instructions.

Description

Under certain conditions, when running the nsDocShell destructor, a race condition can cause a use-after-free. We are aware of targeted attacks in the wild abusing this flaw. This vulnerability affects Thunderbird < 68.7.0, Firefox < 74.0.1, and Firefox ESR < 68.6.1.

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HExploitability: 2.2 | Impact: 5.9

Affected Packages7 packages

CVEListV5mozilla/firefoxunspecified74.0.1
NVDmozilla/firefox< 68.6.1+1
CVEListV5mozilla/firefox_esrunspecified68.6.1
CVEListV5mozilla/thunderbirdunspecified68.7.0
NVDmozilla/thunderbird< 68.7.0

🔴Vulnerability Details

7
GHSA
GHSA-cv8q-mpvf-42h2: Under certain conditions, when running the nsDocShell destructor, a race condition can cause a use-after-free2022-05-24
CVEList
CVE-2020-6819: Under certain conditions, when running the nsDocShell destructor, a race condition can cause a use-after-free2020-04-24
OSV
CVE-2020-6819: Under certain conditions, when running the nsDocShell destructor, a race condition can cause a use-after-free2020-04-24
OSV
thunderbird vulnerabilities2020-04-21
OSV
thunderbird vulnerabilities2020-04-13

📋Vendor Advisories

8
CISA
Mozilla Firefox And Thunderbird Use-After-Free Vulnerability2021-11-03
Ubuntu
Thunderbird vulnerabilities2020-04-21
Ubuntu
Thunderbird vulnerabilities2020-04-13
Ubuntu
Firefox vulnerabilities2020-04-04
Red Hat
Mozilla: Use-after-free while running the nsDocShell destructor2020-04-03

🕵️Threat Intelligence

4
Qualys
Managing CISA Known Exploited Vulnerabilities with Qualys VMDR | Qualys2022-02-23
Securelist
IT threat evolution Q2 2020. PC statistics2020-09-03
Securelist
IT threat evolution Q2 2020. PC statistics2020-09-03
Tenable
CVE-2020-6819, CVE-2020-6820: Critical Mozilla Firefox Zero-Day Vulnerabilities Exploited in the Wild2020-04-03

📐Framework References

2
CWE
Use After Free
CWE
Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

💬Community

1
Bugzilla
CVE-2020-6819 Mozilla: Use-after-free while running the nsDocShell destructor2020-04-04
CVE-2020-6819 — Race Condition in Mozilla Firefox | cvebase