CVE-2020-6820 KEV
8.1
HIGH · CVSS 3.1 · EPSS 7.1% (pctl 94)
Patch first
On CISA KEV — known exploited in the wild, due 2022-05-03.
Description
Under certain conditions, when handling a ReadableStream, 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.
Scoring
| CVSS | 8.1 (HIGH, v3.1) |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 7.06% — more likely to be exploited than 94% of all CVEs |
| Weakness | CWE-362 |
| On CISA KEV | yes — remediate by 2022-05-03 |
| Public exploit | none known |
| Published | 2020-04-24 |
| Last modified | 2026-06-17 |
CISA KEV
| Name | Mozilla Firefox And Thunderbird Use-After-Free Vulnerability |
|---|---|
| Added | 2021-11-03 |
| Due | 2022-05-03 |
| Vendor / product | Mozilla / Firefox and Thunderbird |
| Ransomware use | none reported |
Affected (2)
| Vendor | Product |
|---|---|
| mozilla | firefox |
| mozilla | thunderbird |
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1626728
- https://usn.ubuntu.com/4335-1/
- https://www.mozilla.org/security/advisories/mfsa2020-11/
- https://www.mozilla.org/security/advisories/mfsa2020-14/
- https://bugzilla.mozilla.org/show_bug.cgi?id=1626728
- https://usn.ubuntu.com/4335-1/
- https://www.mozilla.org/security/advisories/mfsa2020-11/
- https://www.mozilla.org/security/advisories/mfsa2020-14/
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-6820
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