The svn protocol parser trusts the indicated length of a URI string sent by a client. This allows a client to specify a very long string, thereby causing svnserve to allocate enough memory to hold that string. This may cause a Denial of Service. Alternately, given a string that causes an integer overflow in the variable holding the string length, the server might allocate less memory than required, allowing a heap overflow. This heap overflow may then be exploitable, allowing remote code execution. The attacker does not need read or write access to the Subversion repository being served, since even un-authenticated users can send svn protocol requests.