Description
Tor before 0.2.1.29 and 0.2.2.x before 0.2.2.21-alpha does not properly check the amount of compression in zlib-compressed data, which allows remote attackers to cause a denial of service via a large compression factor.
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 | 0.2.1.29-1 | — |
| Debian 13 | tor | 0.2.1.29-1 | — |
| Debian 12 | tor | 0.2.1.29-1 | — |
| Debian 5.0 | tor | 0.2.1.29-1~lenny+1 | DSA-2148-1 |
Advisories 1
- DSA-2148-1 tor - several Debian Security (DSA / DLA) · Mar 9, 2026
References
- [or-announce] 20110117 Tor 0.2.1.29 is released (security patches) mailing-list
- ADV-2011-0131 vdb-entry
- https://gitweb.torproject.org/tor.git/blob/refs/heads/release-0.2.2:/ChangeLog
- https://trac.torproject.org/projects/tor/ticket/2324
- 42907 third-party-advisory
- http://blog.torproject.org/blog/tor-02129-released-security-patches
- 1024980 vdb-entry
- ADV-2011-0132 vdb-entry
- DSA-2148 vendor-advisory
- 42905 third-party-advisory
- [oss-security] 20110118 Re: CVE request: tor mailing-list
- 45832 vdb-entry