SECURITY ADVISORY ================== A serious issue has been found in the Windows SSL versions of UnrealIRCd 3.2.9 and 3.2.10-rc1. This issue allows someone to remotely crash the server. Admins of affected systems should upgrade immediately. Note that only Windows versions with SSL support are affected. ==[ AFFECTED VERSIONS ]== Vulnerable versions: * 3.2.9 on Windows with SSL support * 3.2.10-rc1 on Windows with SSL support Not vulnerable: * 3.2.9 and 3.2.10-rc1 on *NIX (Linux, FreeBSD, ..) * 3.2.9 and 3.2.10-rc1 on Windows without SSL support * 3.2.9-winsslfix and 3.2.10-rc1-winsslfix * 3.2.8.1 and earlier If you are unsure which version you are using, then follow this procedure: Type /VERSION on IRC (on some clients you might have to type /QUOTE VERSION) This should return a string like: Unreal3.2.9. server.name FhinWXeOoZE This contains the version number, the server name, and the compile flags. You are vulnerable if ALL these three conditions are met: * The version is 'Unreal3.2.9' or 'Unreal3.2.10-rc1' * The compile flags contain a 'W' (this means you're on Windows) * The compile flags contain a lower case 'e' (this means you're using the * SSL version) Fixed Windows SSL versions can be identified by having 'winsslfix' in their version name. ==[ SHOULD I UPGRADE? ]== If you are using any of the vulnerable versions then you should upgrade immediately as this is a serious issue. Unfortunately there are no mitigating factors: even if you don't actually use SSL, or if you have password-protected your server or hub, then you are still vulnerable to this particular attack. ==[ FIXED VERSIONS ]== New Windows SSL versions are available from: http://www.unrealircd.com/ There's no update for *NIX or the non-SSL Windows version, as these are safe and thus do not require any update. ==[ IMPACT ]== This issue will result in a direct server crash. There's no possibility to execute any code, nor is there any information disclosure. ==[ CVSS ]== CVSS v2.0 report: Confidentiality Impact: None Integrity Impact: None Availability Impact: Complete Access Vector: Network Access Complexity: Low Authentication: None CVSS Base Score: 7.8 Availability of exploit: Proof of concept code[*] Type of fix available: Official fix CVSS Temporal Score: 6.1 [*] Proof of concept / exploit is currently not public. This is expected to change soon after the release of this security bulletin. ==[ TIMELINE ]== Times are in UTC 2012-11-11 19:20 Bug reported 2012-11-12 11:03 Bug confirmed by developer 2012-11-12 11:22 Bug traced, fix available 2012-11-12 13:45 Fixed versions compiled and packaged 2012-11-12 14:00 Security announcement ==[ SOURCE ]== This advisory (and updates to it, if any) is posted to: http://www.unrealircd.com/txt/unrealsecadvisory.20121112.txt