Published: 10 August 2017
A maliciously constructed svn+ssh:// URL would cause Subversion clients before 1.8.19, 1.9.x before 1.9.7, and 1.10.0.x through 1.10.0-alpha3 to run an arbitrary shell command. Such a URL could be generated by a malicious server, by a malicious user committing to a honest server (to attack another user of that server's repositories), or by a proxy server. The vulnerability affects all clients, including those that use file://, http://, and plain (untunneled) svn://.
From the Ubuntu security team
Joern Schneeweisz discovered that Subversion did not properly handle host names in 'svn+ssh://' URLs. A remote attacker could use this to construct a subversion repository that when accessed could run arbitrary code with the privileges of the user.
CVSS 3 base score: 9.8