Mozilla Firefox And Thunderbird Use-After-Free Vulnerability
Mozilla Firefox and Thunderbird contain a race condition vulnerability when handling a ReadableStream under certain conditions. The race condition creates a use-after-free vulnerability, causing unspecified impacts.
A remote attacker, without authentication, can achieve full data confidentiality loss, arbitrary modification of data, complete denial of service or system unavailability. Federal agencies are required to remediate by 2022-05-03 under CISA BOD 22-01.
This is a Race Condition (CWE-362) vulnerability in Mozilla Firefox and Thunderbird. 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. Exploitation requires remote network access, higher attack complexity, no authentication required, and no user interaction required.
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Phishing link
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Malicious file
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Server compromised
Probably yes if any of these apply:
CISA added this CVE to the Known Exploited Vulnerabilities catalog on 2021-11-03 based on evidence of active exploitation in the wild. Federal agencies required to remediate by 2022-05-03.
Manual remediation steps
Apply the Vendor Patch
This vulnerability is in the CISA Known Exploited Vulnerabilities catalog — apply the vendor's security update as soon as possible.
CISA required action: Apply updates per vendor instructions.
References
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References