Hash-Kollision in librsync
ID: | FEDORA-2015-3497 |
Distribution: | Fedora |
Plattformen: | Fedora 21 |
Datum: | Fr, 20. März 2015, 00:04 |
Referenzen: | http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-8242 |
Applikationen: | librsync |
Originalnachricht |
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Name : librsync Product : Fedora 21 Version : 1.0.0 Release : 1.fc21 URL : http://librsync.sourcefrog.net/ Summary : Rsync libraries Description : librsync implements the "rsync" algorithm, which allows remote differencing of binary files. librsync computes a delta relative to a file's checksum, so the two files need not both be present to generate a delta. This library was previously known as libhsync up to version 0.9.0. The current version of this package does not implement the rsync network protocol and uses a delta format slightly more efficient than and incompatible with rsync 2.4.6. -------------------------------------------------------------------------------- Update Information: Changes in librsync 1.0.0 (2015-01-23) ====================================== * SECURITY: CVE-2014-8242: librsync previously used a truncated MD4 "strong" check sum to match blocks. However, MD4 is not cryptographically strong. It's possible that an attacker who can control the contents of one part of a file could use it to control other regions of the file, if it's transferred using librsync/rdiff. For example this might occur in a database, mailbox, or VM image containing some attacker-controlled data. To mitigate this issue, signatures will by default be computed with a 256-bit BLAKE2 hash. Old versions of librsync will complain about a bad magic number when given these signature files. Backward compatibility can be obtained using the new `rdiff sig --hash=md4` option or through specifying the "signature magic" in the API, but this should not be used when either the old or new file contain untrusted data. Deltas generated from those signatures will also use BLAKE2 during generation, but produce output that can be read by old versions. See https://github.com/librsync/librsync/issues/5. Thanks to Michael Samuel |