CVE-2020-6820 (GCVE-0-2020-6820)

Vulnerability from cvelistv5 – Published: 2020-04-24 15:56 – Updated: 2025-10-21 23:35
VLAI? CISA
Summary
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.
Severity ?
8.1 (High)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
  • Use-after-free when handling a ReadableStream
Assigner
References
Impacted products
Vendor Product Version
Mozilla Thunderbird Affected: unspecified , < 68.7.0 (custom)
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    Mozilla Firefox Affected: unspecified , < 74.0.1 (custom)
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    Mozilla Firefox ESR Affected: unspecified , < 68.6.1 (custom)
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CISA Known Exploited Vulnerability
Data from the CISA Known Exploited Vulnerabilities Catalog

Date added: 2021-11-03

Due date: 2022-05-03

Required action: Apply updates per vendor instructions.

Used in ransomware: Unknown

Notes: https://nvd.nist.gov/vuln/detail/CVE-2020-6820

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}


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Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.