CVE-2018-0490 Null dereference in Tor

What is CVE-2018-0490?

CVE-2018-0490 is a high-severity vulnerability in Debian Debian Linux, published on 5 Mar 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

An issue was discovered in Tor before 0.2.9.15, 0.3.1.x before 0.3.1.10, and 0.3.2.x before 0.3.2.10. The directory-authority protocol-list subprotocol implementation allows remote attackers to cause a denial of service (NULL pointer dereference and directory-authority crash) via a misformatted relay descriptor that is mishandled during voting.

Weakness: CWE-476

Which versions are affected by CVE-2018-0490?

It affects 2 products.

Products include Debian Debian Linux, Torproject Tor.

How do I fix CVE-2018-0490?

Upgrade to a fixed version.

Is CVE-2018-0490 being exploited?

There is no known exploitation of CVE-2018-0490 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2018-0490, DSA-4183-1, GHSA-f8j8-3mmq-3xxf, UBUNTU-CVE-2018-0490.