Squid 3.5.13 / 4.0.4 / 4.0.5 Server Connection Error Handling DoS
Medium Nessus Plugin ID 89052
SynopsisThe remote proxy server is potentially affected by a denial of service vulnerability.
DescriptionAccording to its banner, the version of Squid running on the remote host is 3.5.13, 4.0.4, or 4.0.5. It is, therefore, potentially affected by a denial of service vulnerability due to improper handling of server connection errors in the FwdState::connectedToPeer() function. A remote attacker can exploit this, via a misconfigured client or server, to cause a denial of service condition when connecting to TLS or SSL servers.
Note that only servers built with the --with-openssl option are vulnerable.
Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number. The patch released to address this issue does not update the version given in the banner. If the patch has been applied properly, and the service has been restarted, consider this to be a false positive.
SolutionUpgrade to Squid version 3.5.14 / 4.0.6 or later. Alternatively, apply the vendor-supplied patch.