Your message dated Fri, 01 Mar 2013 05:32:53 +0000 with message-id <[email protected]> and subject line Bug#701839: fixed in sudo 1.8.5p2-1+nmu1 has caused the Debian Bug report #701839, regarding sudo: CVE-2013-1776 potential bypass of sudo tty_tickets constraints to be marked as done.
This means that you claim that the problem has been dealt with. If this is not the case it is now your responsibility to reopen the Bug report if necessary, and/or fix the problem forthwith. (NB: If you are a system administrator and have no idea what this message is talking about, this may indicate a serious mail system misconfiguration somewhere. Please contact [email protected] immediately.) -- 701839: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=701839 Debian Bug Tracking System Contact [email protected] with problems
--- Begin Message ---Package: sudo Severity: important Tags: security Hi, the following vulnerability was published for sudo. CVE-2013-1776[0]: (from the upstream report) Sudo 1.8.6p7 and 1.7.10p6 are now available which include a fix for the following bug: Potential bypass of sudo tty_tickets constraints Summary: When a user successfully authenticates with sudo, a time stamp file is updated to allow that user to continue running sudo without requiring a password for a preset time period (five minutes by default). This time stamp file can either be common to all of a user's terminals, or it can be specific to the particular terminal the user authenticated themselves on. The terminal-specific time stamp file behavior can be controlled using the "tty_tickets" option in the sudoers file. This option has been enabled by default since sudo 1.7.4. Prior to sudo 1.7.4, the default was to use a single time stamp for all the user's sessions. A vulnerability exists because the user can control which terminal the standard input, output and error file descriptors (0-2) refer to. A malicious user could use this to run commands via sudo without authenticating, so long as there exists a terminal the user has access to where a sudo command was successfully run by that same user within the password timeout period (usually five minutes). The vulnerability does not permit a user to run commands other than those allowed by the sudoers policy. Sudo versions affected: Sudo 1.3.5 through 1.7.10p6 and sudo 1.8.0 through 1.8.6p7 when the "tty_tickets" option is enabled. This option is enabled by default in sudo 1.7.4 and above. Details: The vulnerability can be triggered when the standard input, output and error file descriptors (0-2) of a process are closed and a different terminal device is opened and connected to those descriptors. When sudo tries to determine the terminal device via the ttyname() function, it will get the name of the other terminal instead. The core problem is that while ttyname() can be used to determine the name of the terminal device connected to a specific file descriptor, there is no portable way to determine the name of the terminal associated with the session the process belongs to. However, on many systems it is possible to determine this by using the /proc file system or the sysctl() function. Most operating systems that have the /proc file system provide a way to determine the controlling terminal device number for a process; this information is used by the ps command for example. On Linux, this is the tty_nr field in /proc/self/stat (the seventh entry). On systems with an SVR4-style /proc, this is the pr_ttydev member of struct psinfo, which comes from /proc/self/psinfo. Most BSD systems that support the sysctl() function also provide a way to get the terminal device number via the KERN_PROC_PID sysctl. By mapping this device number to a file name, it is possible to get the name of the terminal file without resorting to ttyname(). Sudo began using this method to determine the process's terminal starting with version 1.8.5 and 1.7.10. However, sudo still used the ttyname() function as a fall back when no controlling terminal was found via /proc or sysctl(). This allowed a malicious process to cause sudo to use ttyname() simply by creating a new session without a controlling tty before executing sudo. In sudo 1.8.6p6 and 1.7.10p5, this fall back behavior was removed. This fixed the vulnerability for systems where the process's controlling terminal could be determined via /proc or sysctl(). Sudo 1.8.6p7 and 1.7.10p6 contain an additional fix for systems without /proc or sysctl() that stores the POSIX session ID in the time stamp file itself. The controlling terminal is specific to the POSIX session it is associated with. It is not possible for two processes in different sessions to have the same controlling terminal. Sudo will now compare the current session ID with the one in the time stamp file and ignore the time stamp file if the session ID does not match. This has the additional benefit of making it much less likely that a user will be able to reuse the time stamp file after logging out and back in again on the same terminal. Impact: A (potentially malicious) program run by a user with sudo access may be able to bypass the "tty_ticket" constraints. In order for this to succeed there must exist on the machine a terminal device that the user has previously authenticated themselves on via sudo within the last time stamp timeout (5 minutes by default). This program may use sudo's -n flag to "probe" the terminals in question to see if there is an active time stamp file for the user. Prior to sudo 1.8.6 and 1.7.10, if a password was required when the -n flag was specified the failure would not be logged, allowing the program to perform such probes without being detected. The successful command (if any), would still be logged. Fix: The bug is fixed in sudo 1.8.6p7 and 1.7.10p6. Credit: Ryan Castellucci brought the initial ttyname() issue to my attention. Subsequently, James Ogden discovered that using setsid() to create a new session would cause sudo to fall back to using ttyname(). Other shortcomings in sudo's "tty_tickets" functionality have been known and discussed openly for some time. There is a long discussion about them at: https://bugs.launchpad.net/ubuntu/+source/sudo/+bug/87023 If you fix the vulnerability please also make sure to include the CVE (Common Vulnerabilities & Exposures) id in your changelog entry. For further information see: [0] http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2013-1776 http://security-tracker.debian.org/tracker/CVE-2013-1776 Please adjust the affected versions in the BTS as needed. -- Nico Golde - http://www.ngolde.de - [email protected] - GPG: 0xA0A0AAAA
pgpiB6P7HlOrs.pgp
Description: PGP signature
--- End Message ---
--- Begin Message ---Source: sudo Source-Version: 1.8.5p2-1+nmu1 We believe that the bug you reported is fixed in the latest version of sudo, which is due to be installed in the Debian FTP archive. A summary of the changes between this version and the previous one is attached. Thank you for reporting the bug, which will now be closed. If you have further comments please address them to [email protected], and the maintainer will reopen the bug report if appropriate. Debian distribution maintenance software pp. Michael Gilbert <[email protected]> (supplier of updated sudo package) (This message was generated automatically at their request; if you believe that there is a problem with it please contact the archive administrators by mailing [email protected]) -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Format: 1.8 Date: Fri, 01 Mar 2013 03:26:37 +0000 Source: sudo Binary: sudo sudo-ldap Architecture: source amd64 Version: 1.8.5p2-1+nmu1 Distribution: unstable Urgency: high Maintainer: Bdale Garbee <[email protected]> Changed-By: Michael Gilbert <[email protected]> Description: sudo - Provide limited super user privileges to specific users sudo-ldap - Provide limited super user privileges to specific users Closes: 701838 701839 Changes: sudo (1.8.5p2-1+nmu1) unstable; urgency=high . * Non-maintainer upload by the Security Team. * Fix cve-2013-1775: authentication bypass when the clock is set to the UNIX epoch [00:00:00 UTC on 1 January 1970] (closes: #701838). * Fix cve-2013-1776: session id hijacking from another authorized tty (closes: #701839). Checksums-Sha1: 05a116304df73e20148759ebfecee6f9dfe96725 2589 sudo_1.8.5p2-1+nmu1.dsc 2052bd6151dc62d71715762e6a192df404a9235f 26822 sudo_1.8.5p2-1+nmu1.debian.tar.gz b47bb046d0fa4ce2c1743c1e45e9d42a6c5251c4 842220 sudo_1.8.5p2-1+nmu1_amd64.deb cd0baf39ba2dc417d3dd4bc97e95e4732d176607 863082 sudo-ldap_1.8.5p2-1+nmu1_amd64.deb Checksums-Sha256: aefcde86fe6b74b5ce1affd52b057dc68c969ced29f1292ac3a937763d2380d8 2589 sudo_1.8.5p2-1+nmu1.dsc 15b44cd8f4542352b20629d8fe786d14d47e3b35fd86a05648658ec390423835 26822 sudo_1.8.5p2-1+nmu1.debian.tar.gz 557c3147b18d5f09bdb60a83ad6ce30a5243d903fbad714beca233cb856cb8b2 842220 sudo_1.8.5p2-1+nmu1_amd64.deb 545bd3a0d15ceaa9d9c71edd61f196dee0262ea762750e61ea28df32fac40259 863082 sudo-ldap_1.8.5p2-1+nmu1_amd64.deb Files: 0d259053017092470a1d804503ee3a42 2589 admin optional sudo_1.8.5p2-1+nmu1.dsc 149d2138846fc7121cfcd3ff4df7fea9 26822 admin optional sudo_1.8.5p2-1+nmu1.debian.tar.gz 3df5acae3e544aba6916085f6a169181 842220 admin optional sudo_1.8.5p2-1+nmu1_amd64.deb f3d220876a4edde1a03ab41d609bfda4 863082 admin optional sudo-ldap_1.8.5p2-1+nmu1_amd64.deb -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQQcBAEBCAAGBQJRMDsnAAoJELjWss0C1vRzsYEf/2aKdfhZH9f+IzeQ0il8q8Ax 9HgqOT0uD15LWPOoy5nNNYLHACtBeuYte6l72dfDbCoUz+o220PFbhQtOoXuwAjn wj0joyPHmiHYW4+vvRYoJ5z56UC836Hyg2FlEVVnN2f16rSrAw0XQtfkvm8B2s9N Coosf0ue6HElezXa0uznq0F49Spv9TJ324nneslEH8uBg/1yvPp14HQs6EA+a0/W u7IV1rxWAY+W4PD5+j5sSbOI5EiibsMPidNrrrdZkLue4RNPL8PIRguwww8A+O3a ZuUAS6PX/8TAr345GzqyR0Navj+hnyWre+XRhXrKhMfTbV2cPwGoduRhma4XtNdw dvElLNPtAs9xQHjJoQp9K9HTKT8OJa6kQxX4Iv4qTdkutIpEeqZ4UcW4h9802Iom EDsTAWo6rXOdOm8ccRaNxs2xswC0GiO0pX2XbsUIsJtN7lWhG3s1sVBO9kw506CA f4VfuU+hnvHYtUQ5xizVs6OzWGF1hu4Z/rrjxzp6rfqJJb22OuLgp8K3ZIHjsacX WDys1nPSDflIVz4Y0YlPSXCk3qYaFKC/XZEBYPOFHBTmro6nIJfa9aZpmDYgm0jE 9z3qtE1whV4O+7bEZcl/LyKHqQO2GsPZEZl0GWolSnAsIUXZDS7TYY7UVXmOIcFY b0Lqtr+/Zkzi+sULl7vB1rrOzEGYhQ3Yb9qu+V7VoGGt1HhVwphzcvuiMmcGVswu pAsgTUpvwRy4NKxxRwjRm27dyBtOLT8p8Xq66okF5EgGnRezbqiZFDUvO5VEQM/G +YIB/brpKD4YkuQb2zdXAu31oPRNIKFy6Abs1R1aFMVNnY56cgy1G6zPezmdHgwu irLLGKU7RB6VENJdncn28sdiXDgBFchFHRERinGutRqZCzPjSe2Omvsf9Q4CuqAx s8WgLnFGYCCQG62a8cmqr+DcUuhu5+oaSUrMWJVsyJ2KmBbgHt7J4RcsaB7IuHId QB4ebrNvIbs7+G0Z/AG3DURFjGJSBCBglMm6qZFIuBwitj7b3qCUhTi3Bdtf1bFF eXNSqHoF5gbXWIp6vAjmKffc0mrZTdQBXOANtxxHWS8D7nhcf95dkn8C6tDjtGKi pX2Ab4G8CEKGdUmRvnrCqG7GkNNNNI8exTzxtwRlFqTpZwFNKQVqojvkn4elfOsl hKmwSJWQbMnnpsRB1l7tHDRfj000dgDtXAmNNmdsaLqdeYOZ+bMS1zKHrN8iVYIu mhuc4TT7iRtkOAeSYY7MWIV47vBRhXlAWU8UGqXzQpH2mG/Jns6aBCCiKFJCUo5Q DUlwrsSUb7jOrPvGd/as2gKmwushPLBE37KgsNv7SuVQVne7SAPkhOUrWN1cX2k= =pgRW -----END PGP SIGNATURE-----
--- End Message ---
