** Project changed: libmemcached => ubuntu-translations ** No longer affects: ubuntu-translations
-- You received this bug notification because you are a member of Ubuntu Translations Coordinators, which is subscribed to Ubuntu Translations. Matching subscriptions: Ubuntu Translations bug mail https://bugs.launchpad.net/bugs/1573594 Title: Missing null termination in PROTOCOL_BINARY_CMD_SASL_LIST_MECHS response handling Status in libmemcached package in Ubuntu: Fix Released Status in libmemcached source package in Trusty: Fix Committed Status in libmemcached source package in Xenial: Fix Committed Status in libmemcached source package in Bionic: Fix Committed Status in libmemcached source package in Cosmic: Fix Committed Status in libmemcached source package in Disco: Fix Released Status in libmemcached package in Debian: New Bug description: [Impact] When connecting to a server using SASL, memcached_sasl_authenticate_connection() reads the list of supported mechanisms [1] from the server via the command PROTOCOL_BINARY_CMD_SASL_LIST_MECHS. The server's response is a string containing supported authentication mechanisms, which gets stored into the (uninitialized) destination buffer without null termination [2]. The buffer then gets passed to sasl_client_start [3] which treats it as a null-terminated string [4], reading uninitialised bytes in the buffer. As the buffer lives on the stack, an attacker that can put strings on the stack before the connection gets made, might be able to tamper with the authentication. [1] libmemcached/sasl.cc:174 [2] libmemcached/response.cc:619 [1] libmemcached/sasl.cc:231 [3] http://linux.die.net/man/3/sasl_client_start [Test Case] This bug is difficult to reproduce since it depends on the contents of the stack. However, here is a test case using the fix on Bionic that shows that this fix does not cause any problems. For testing you need 1) A memcached server. You can setup one by following the instructions in [1], or (what I did) create one in the cloud [2]. 2) A client test program to connect to the memcached server. One can be found in [3]. This simple test connects to a memcache server and test basic get/set operations. Copy paste the C code into a file (sals_test.c) and compile with : gcc -o sasl_test -O2 sasl_test.c -lmemcached -pthread 3) On a machine with the updated version of libmemcached in which the fix is applied : jo@bionic-vm:~$ dpkg -l | grep libmemcached ii libhashkit-dev:amd64 1.0.18-4.2ubuntu0.18.04.1 amd64 libmemcached hashing functions and algorithms (development files) ii libhashkit2:amd64 1.0.18-4.2ubuntu0.18.04.1 amd64 libmemcached hashing functions and algorithms ii libmemcached-dbg:amd64 1.0.18-4.2ubuntu0.18.04.1 amd64 Debug Symbols for libmemcached ii libmemcached-dev:amd64 1.0.18-4.2ubuntu0.18.04.1 amd64 C and C++ client library to the memcached server (development files) ii libmemcached-tools 1.0.18-4.2ubuntu0.18.04.1 amd64 Commandline tools for talking to memcached via libmemcached ii libmemcached11:amd64 1.0.18-4.2ubuntu0.18.04.1 amd64 C and C++ client library to the memcached server ii libmemcachedutil2:amd64 1.0.18-4.2ubuntu0.18.04.1 amd64 library implementing connection pooling for libmemcached Run the sals_test binary : #./sasl_test [username] [password] [server] In my case using the credentials and the server created in step 1 : jo@bionic-vm:~$ ./sasl_test 88BAB0 1A99094B77C8935ED9F1461C767DB1F9 mc2.dev.eu.ec2.memcachier.com Get/Set success! [1] https://blog.couchbase.com/sasl-memcached-now-available/ [2] https://www.memcachier.com/ [3] https://blog.memcachier.com/2014/11/05/ubuntu-libmemcached-and-sasl-support/ [Regression Potential] This fix initialises the buffer to 0. Any potential regression may include failure of the authentication when using SASL. [Other Info] This bug affects trusty and later. * rmadison: libmemcached | 1.0.8-1ubuntu2 | trusty | source libmemcached | 1.0.18-4.1 | xenial | source libmemcached | 1.0.18-4.2 | bionic | source libmemcached | 1.0.18-4.2 | cosmic | source libmemcached | 1.0.18-4.2 | disco | source * Debian bug: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=919696 * Upstream seems pretty quiet since 2014 Unfortunately, because the project seems more or less dead ... it seems like we won't be able submit anything upstream and go straight to fixing Debian and Ubuntu. - Repo: bzr branch lp:libmemcached - Last commit: revno: 1113 [merge] committer: Continuous Integration <c...@tangent.org> branch nick: workspace timestamp: Sun 2014-02-16 03:31:37 -0800 message: Merge bzr://soup.haus/ Build: jenkins-Libmemcached-473 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/libmemcached/+bug/1573594/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-translations-coordinators Post to : ubuntu-translations-coordinators@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-translations-coordinators More help : https://help.launchpad.net/ListHelp