Описание
Twisted SSH client and server deny of service during SSH handshake.
Impact
The Twisted SSH client and server implementation naively accepted an infinite amount of data for the peer's SSH version identifier.
A malicious peer can trivially craft a request that uses all available memory and crash the server, resulting in denial of service. The attack is as simple as nc -rv localhost 22 < /dev/zero.
Patches
The issue was fix in GitHub commit https://github.com/twisted/twisted/commit/98387b39e9f0b21462f6abc7a1325dc370fcdeb1
A fix is available in Twisted 22.2.0.
Workarounds
- Limit access to the SSH server only to trusted source IP addresses.
- Connect over SSH only to trusted destination IP addresses.
References
Reported at https://twistedmatrix.com/trac/ticket/10284 Discussions at https://github.com/twisted/twisted/security/advisories/GHSA-rv6r-3f5q-9rgx
For more information
Found by vin01
Ссылки
- https://github.com/twisted/twisted/security/advisories/GHSA-rv6r-3f5q-9rgx
- https://nvd.nist.gov/vuln/detail/CVE-2022-21716
- https://github.com/twisted/twisted/commit/89c395ee794e85a9657b112c4351417850330ef9
- https://github.com/twisted/twisted/commit/98387b39e9f0b21462f6abc7a1325dc370fcdeb1
- https://github.com/pypa/advisory-database/tree/main/vulns/twisted/PYSEC-2022-160.yaml
- https://github.com/twisted/twisted/releases/tag/twisted-22.2.0
- https://lists.debian.org/debian-lts-announce/2022/03/msg00009.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7U6KYDTOLPICAVSR34G2WRYLFBD2YW5K
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GLKHA6WREIVAMBQD7KKWYHPHGGNKMAG6
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/7U6KYDTOLPICAVSR34G2WRYLFBD2YW5K
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GLKHA6WREIVAMBQD7KKWYHPHGGNKMAG6
- https://security.gentoo.org/glsa/202301-02
- https://twistedmatrix.com/trac/ticket/10284
- https://www.oracle.com/security-alerts/cpuapr2022.html
Пакеты
twisted
>= 21.7.0, < 22.2.0
22.2.0
Связанные уязвимости
Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 22.2.0, Twisted SSH client and server implement is able to accept an infinite amount of data for the peer's SSH version identifier. This ends up with a buffer using all the available memory. The attach is a simple as `nc -rv localhost 22 < /dev/zero`. A patch is available in version 22.2.0. There are currently no known workarounds.
Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 22.2.0, Twisted SSH client and server implement is able to accept an infinite amount of data for the peer's SSH version identifier. This ends up with a buffer using all the available memory. The attach is a simple as `nc -rv localhost 22 < /dev/zero`. A patch is available in version 22.2.0. There are currently no known workarounds.
Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 22.2.0, Twisted SSH client and server implement is able to accept an infinite amount of data for the peer's SSH version identifier. This ends up with a buffer using all the available memory. The attach is a simple as `nc -rv localhost 22 < /dev/zero`. A patch is available in version 22.2.0. There are currently no known workarounds.
Twisted is an event-based framework for internet applications, support ...
