CVE-2021-39246
Published: 24 September 2021
Summary
CVE-2021-39246 is a medium-severity Insertion of Sensitive Information into Log File (CWE-532) vulnerability in Torproject Tor Browser. Its CVSS base score is 6.1 (Medium).
Operationally, ranked at the 28.6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-25608
Vulnerability details
Tor Browser through 10.5.6 and 11.x through 11.0a4 allows a correlation attack that can compromise the privacy of visits to v2 onion addresses. Exact timestamps of these onion-service visits are logged locally, and an attacker might be able to compare…
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them to timestamp data collected by the destination server (or collected by a rogue site within the Tor network).
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Procedures mandate excluding sensitive data from logs to prevent unauthorized exposure via audit records.
Identifies insertion of sensitive data into logs, allowing detection of unauthorized disclosure.
Cross-organizational coordination enables agreement on what data to include in audit logs, directly reducing insertion of sensitive information.
Identifying logging as a data action allows prevention of sensitive information being inserted into log files.
The process of identifying and eradicating spilled information applies directly to sensitive data inserted into log files.
Specific processing rules for sensitive PII categories commonly include restrictions on logging, making insertion of such data into log files less likely.
PIAs detect planned or existing logging of PII and require removal or protection, preventing insertion of sensitive information into logs.
Limits insertion of sensitive operational details into logs by treating such data as key information requiring protection.