PT-2021-22491 · Tor+1 · Tor Browser

Sick.Codes · Published 2021-09-24 · Updated 2021-10-01 · CVE-2021-39246

Positive Technologies (AI Summary)

CVSS v3.1

6.1

Medium

Base vector

AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Name of the Vulnerable Software and Affected Versions Tor Browser versions 10.5.6 and 11.x through 11.0a4

Description The issue 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). This can occur when the --log or --verbose option is used.

Recommendations For Tor Browser versions 10.5.6 and 11.x through 11.0a4, consider disabling the verbose logging feature to minimize the risk of exploitation. Avoid using the --log or --verbose option until a patch is available. At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

Insertion into Log File

Weakness Enumeration

CWE-532

Related Identifiers

CVE-2021-39246

Affected Products

Tor Browser

References · 15

• 🔥 https://github.com/sickcodes/security/blob/master/advisories/SICK-2021-111.md · Exploit
• 🔥 https://sick.codes/sick-2021-111 · Exploit
• https://gitlab.torproject.org/tpo/core/tor/-/merge_requests/434 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-39246 · Security Note
• https://gitlab.torproject.org/tpo/core/tor/-/commit/80c404c4b79f3bcba3fc4585d4c62a62a04f3ed9 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-39246 · Vendor Advisory
• https://t.me/cvenotify/21726 · Telegram Post
• https://t.me/defcon_news/85895 · Telegram Post
• https://t.me/secharvester/11521 · Telegram Post
• https://privacyaffairs.com/cve-2021-39246-tor-vulnerability · Note
• https://t.me/cvenotify/21674 · Telegram Post
• https://t.me/rnetsec/15724 · Telegram Post
• https://t.me/ckure/9525 · Telegram Post
• https://t.me/cibsecurity/29402 · Telegram Post
• https://t.me/cybersecuritytechnologies/4386 · Telegram Post