CVE-2021-39246: torproject tor_browser
Vulnerability summary
CVE-2021-39246 is a medium (CVSS 6.1) vulnerability in torproject tor_browser. EPSS estimates a 0.47% chance of exploitation in the next 30 days, higher than 39.7% of scored vulnerabilities. 2 public exploits are recorded.
Timeline
- 24-09-2021PublishedVulnerability first disclosed.
- 04-08-2024Last modifiedVulnerability information updated.
Description
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 them to timestamp data collected by the destination server (or collected by a rogue site within the Tor network).
CVSS metrics
2 scores · 1 source · 2 versionsEPSS trend
Probability
0.47%
Chance of exploitation in the next 30 days
Percentile
40%
Versus all other CVEs
30-day change
0.00 pp
From 0.47% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
2 foundSecurity
Maturity: poc
Exploit Reference (sick.codes)
Maturity: unknown
Weaknesses
CWE · root causeAffected systems
Torproject1 product
- tor_browser≤ 10.5.6 | 11.0:alpha2 | 11.0:alpha4
1 vendor · 1 product
References
5 links- github.com/sickcodes/security/blob/master/advisories/SICK-2021-111.mdX Refsource MISCExploitThird Party Advisory
- gitlab.torproject.org/tpo/core/tor/-/commit/80c404c4b79f3bcba3fc4585d4c62a62a04f3ed9X Refsource MISCPatchVendor Advisory