CVE-2020-6819
Confirmed PUBLISHEDUnder certain conditions, when running the nsDocShell destructor, a race condition can cause a use-after-free. We are aware of targeted attacks in...
Recommended Action
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
At a Glance
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.
- CVE Published
- Apr 24, 2020
- Exploitation Reported
- Nov 03, 2021
- CVSS
- 8.1 High
- EPSS
- —
Affected Versions
| Vendor | Product | Version | Status |
|---|---|---|---|
| Mozilla |
Thunderbird
|
unspecified to < 68.7.0 |
Affected |
| Mozilla |
Firefox
|
unspecified to < 74.0.1 |
Affected |
| Mozilla |
Firefox ESR
|
unspecified to < 68.6.1 |
Affected |
CVE References
- USN-4335-1 usn.ubuntu.com · Vendor Advisory https://usn.ubuntu.com/4335-1/
- mozilla.org/security/advisories/mfsa2020-14 mozilla.org · CVE Record https://www.mozilla.org/security/advisories/mfsa2020-14/
- mozilla.org/security/advisories/mfsa2020-11 mozilla.org · CVE Record https://www.mozilla.org/security/advisories/mfsa2020-11/
- bugzilla.mozilla.org/show_bug.cgi bugzilla.mozilla.org · CVE Record https://bugzilla.mozilla.org/show_bug.cgi?id=1620818
Recommended Actions
- Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
- Use the Pro API to automate enrichment, telemetry, and workflow delivery for VM, SOC, and CTI pipelines.
Known Exploited Vulnerability Sources
Catalogues that list this CVE as a known exploited vulnerability.
Per-source evidence links for KEV attestations are available through the KEVIntel Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CISA First | 2021-11-03 00:00 UTC |
No detection artifacts or sensor request patterns are available for this CVE yet.
Check back as sensor telemetry and scanner integrations are updated.
Virtual Patch
Compensating WAF rules to help reduce exposure to this CVE. Rule content and deployable vendor exports are available with KEVIntel Enterprise.
KEVIntel does not currently have a virtual patch for this CVE. When available, KEVIntel virtual patches ship as deployable ModSecurity, Cloudflare, and AWS WAF rules.
Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to KEVIntel Enterprise users.
CVSS Scores
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
AV:N/AC:M/Au:N/C:P/I:P/A:P
Exploitation Status
Exploited in the wild
Recorded 2021-11-03 00:00:00 UTC · CISA
Weaknesses (CWE)
-
Use After Free
Timeline
Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.
-
00:00 UTC over 4 years ago00:00 UTC · over 4 years ago
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
15:56 UTC about 6 years ago15:56 UTC · about 6 years ago
CVE published
Vulnerability disclosed publicly
-
00:00 UTC over 6 years ago00:00 UTC · over 6 years ago
CVE ID reserved
Identifier reserved by the CNA
Automate This Intelligence with the Pro API
Confidence scoring, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
Pro API Example
GET /api/v2/pro/kevs/CVE-2020-6819
{
"cve_id": "CVE-2020-6819",
"title": "Under certain conditions, when running the nsDocShell destructor, a race cond...",
"affected_vendor": "Mozilla",
"affected_product": "Thunderbird, Firefox, Firefox ESR",
"affected_versions": [
{ "vendor": "...", "product": "...", "status": "affected", "display_label": "..." }
],
"confidence": "Confirmed",
"cvss_score": 8.1,
"epss_score": null,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "...": "Pro API fields" },
"proof_of_concepts": [ "..." ],
"scanner_integrations": [ "..." ]
}