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MEDIUM5.9

PYSEC-2026-2472

Potential DoS via the Tudoor mechanism in eventlet and dnspython

Quick fix

PYSEC-2026-2472 — eventlet: upgrade to the fixed version with the command below.

pip install --upgrade 'eventlet>=0.35.2'

Details

eventlet before 0.35.2, as used in dnspython before 2.6.0, allows remote attackers to interfere with DNS name resolution by quickly sending an invalid packet from the expected IP address and source port, aka a "TuDoor" attack. In other words, dnspython does not have the preferred behavior in which the DNS name resolution algorithm would proceed, within the full time window, in order to wait for a valid packet. NOTE: dnspython 2.6.0 is unusable for a different reason that was addressed in 2.6.1.

Are you affected?

Enter the version of the package you're using.

Affected packages

PyPI/eventlet
Introduced in: 0Fixed in: 0.35.2
Fixpip install --upgrade 'eventlet>=0.35.2'

References