Description
routerlist.c in Tor before 0.2.2.38 uses a different amount of time for relay-list iteration depending on which relay is chosen, which might allow remote attackers to obtain sensitive information about relay selection via a timing side-channel attack.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | tor | 0.2.3.20-rc-1 | — |
| Debian 13 | tor | 0.2.3.20-rc-1 | — |
| Debian 12 | tor | 0.2.3.20-rc-1 | — |
| Debian 6.0 | tor | 0.2.2.39-1 | DSA-2548-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | tor | 0.2.8.11-1.1 | openSUSE-SU-2024:10423-1 |
Advisories 2
- DSA-2548-1 tor - several Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:10423-1 tor-0.2.8.11-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
References
- GLSA-201301-03 vendor-advisory
- https://gitweb.torproject.org/tor.git/commit/308f6dad20675c42b29862f4269ad1fbfb00dc9a
- [tor-announce] 20120819 Tor 0.2.2.38 is released mailing-list
- 50583 third-party-advisory
- [oss-security] 20120821 Re: CVE Request -- Tor 0.2.2.38: Three issues mailing-list
- https://trac.torproject.org/projects/tor/ticket/6537
- openSUSE-SU-2012:1068 vendor-advisory
- https://gitweb.torproject.org/tor.git/commit/d48cebc5e498b0ae673635f40fc57cdddab45d5b