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Slackware: 2003-252-02 Security: Pop3d Denial of Service Fix

These updates fix a previously hard-coded limit of 256connections-per-minute, after which the given service is disabledfor ten minutes.. [slackware-security] inetd DoS patched (SSA:2003-251-01) Upgraded inetd packages are available for Slackware 8.1, 9.0 and - -current. These fix a previously hard-coded limit of 256 connections-per-minute, after which the given service is disabled for ten minutes. An attacker could use a quick burst of connections every ten minutes to effectively disable a service. Once upon a time, this was an intentional feature of inetd, but in today's world it has become a bug. Even having inetd look at the source IP and try to limit only the source of the attack would be problematic since TCP source addresses are so easily faked. So, the approach we have taken (borrowed from FreeBSD) is to disable this rate limiting "feature" by default. It can be reenabled by providing a -R option on the command-line if desired, but for obvious reasons we do not recommend this. Any site running services through inetd that they would like protected from this simple DoS attack should upgrade to the new inetd package immediately. Here are the details from the Slackware 9.0 ChangeLog: +--------------------------+ patches/packages/inetd-1.79s-i386-2.tgz: Disable inetd's (stupid) connection limiting code which can actually cause a DoS rather than preventing it. The default connections-per-minute is now unlimited. -R 0 also removes limiting (this is now mentioned in the man page as well). Thanks to 3APA3A for reporting this issue. (* Security fix *) +--------------------------+ WHERE TO FIND THE NEW PACKAGES: +-----------------------------+ Updated package for Slackware 8.1: Updated package for Slackware 9.0: Updated package for Slackware -current: MD5 SIGNATURES: +-------------+ Slackware 8.1 package: 018502403c63b7257b79deea55a51db5 inetd-1.79s-i386-2.tgz Slackware 9.0 package: c844eb828e87ec9b263d4a7879a895d8 inetd-1.79s-i386-2.tgz Slackware -currentpackage: acf65702ffd747066c2bcd26f28f8ca4 inetd-1.79s-i486-2.tgz INSTALLATION INSTRUCTIONS: +------------------------+ Kill inetd: # killall inetd Upgrade using upgradepkg (as root): # upgradepkg inetd-1.79s-i386-2.tgz Restart inetd: # inetd +-----+ Slackware Linux Security Team slackware This email address is being protected from spambots. You need JavaScript enabled to view it. . Debian resolves sshd security vulnerability. Be sure to upgrade sshd components to prevent potential breaches due to unauthorized access.. inetd Security, DoS Protection, Linux Updates, Service Patch, Slackware Security. . Severity: Important. LinuxSecurity.com Team

Sep 09, 2003 •Important Slackware