Medium

Potential DoS via the Tudoor mechanism in eventlet and dnspython

  • Disclosed: 11.04.2024
  • Updated: 11.10.2026 15:17

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.

Affected software

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PlatformPackageVulnerable versionsFixed in
Python (PyPI) dnspython < 2.6.1 2.6.1
Python (PyPI) eventlet < 0.35.2 0.35.2

References

CVSS score 5.9/10
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE)
CWE-696
Platform
Python (PyPI)
Package
dnspython, eventlet
Disclosed
11.04.2024
Updated
11.10.2026 15:17

Sources and licenses

OSV / GitHub Advisory Database - PYSEC-2026-1307 - PyPA Advisory Database; CC BY 4.0

OSV / GitHub Advisory Database - PYSEC-2026-2472 - PyPA Advisory Database; CC BY 4.0

OSV / GitHub Advisory Database - GHSA-3rq5-2g8h-59hc - CC BY 4.0

Vulnerability history: dnspython

All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.

This is the only known vulnerability of this package.

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