Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.10.0rc1, twisted.words.protocols.irc.IRC.dataReceived retains all bytes received without a line feed in its per-connection buffer and applies no maximum line length. The twisted.words.service.IRCUser server subclass inherits this behavior, and buffering occurs before PASS, NICK, or USER authentication commands.
An unauthenticated connection can continuously grow the buffer until the shared server process runs out of memory and drops all users. This issue is fixed in version 26.10.0rc1.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service
CVSS Vector v3.1
Weakness Type (CWE)
Vulnerable Products
twisted:twisted
References 5
https://github.com/twisted/twisted/security/advisories/GHSA-53xc-49m8-p798
https://github.com/twisted/twisted/security/advisories/GHSA-53xc-49m8-p798
https://github.com/twisted/twisted/pull/12771
https://github.com/twisted/twisted/pull/12771
https://github.com/twisted/twisted/commit/01f8cff7753c1edac132380b2ea939fa6bdba…
https://github.com/twisted/twisted/commit/01f8cff7753c1edac132380b2ea939fa6bdbab30
https://github.com/twisted/twisted/commit/ac90fb7b0ab73688a581fcd9a7c0577ec8ca3…
https://github.com/twisted/twisted/commit/ac90fb7b0ab73688a581fcd9a7c0577ec8ca3059
https://github.com/twisted/twisted/releases/tag/twisted-26.10.0rc1
https://github.com/twisted/twisted/releases/tag/twisted-26.10.0rc1