``` TROVE-2017-010: Remote DoS attack against directory authorities SEVERITY: Medium ALSO TRACKED AS: CVE-2017-8820 SUMMARY: If an attacker uploads a malformed descriptor to a directory authority, lacking a protocol line and not claiming any particular Tor compatibility, the authority will crash when it tries to vote. THE PROBLEM: An attacker who sends a malformatted descriptor to a directory authority can make that directory authority crash by reading a null pointer. The problematic code was introduced in 0.2.9.4-alpha, with the rest of the subprotocols system. FIX: All directory authorities should upgrade to one of the releases with a fix for this issue: 0.2.9.14, 0.3.0.13, 0.3.1.9, or 0.3.2.6-alpha. ```