Tor before 0.3.5.10, 0.4.x before 0.4.1.9, and 0.4.2.x before 0.4.2.7 allows remote attackers to cause a Denial of Service (memory leak), aka TROVE-2020-004. This occurs in circpad_setup_machine_on_circ because a circuit-padding machine can be negotiated twice on the same circuit.

References

• https://nvd.nist.gov/vuln/detail/CVE-2020-10593
• https://security.gentoo.org/glsa/202003-50
• https://trac.torproject.org/projects/tor/ticket/33619
• http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00045.html
• http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00052.html