librsync before 1.0.0 uses a truncated MD4 checksum to match blocks, which makes it easier for remote attackers to modify transmitted data via a birthday attack.

The remote host is affected by the vulnerability described in GLSA-201605-04 (rsync: Multiple vulnerabilities)

    Multiple vulnerabilities have been discovered in rsync. Please review       the CVE identifiers referenced below for details.
  Impact :

    Remote attackers could write arbitrary files via symlink attacks.
  Workaround :

    There is no known workaround at this time.

This update for rsync fixes two security issues :

  - CVE-2014-8242: Checksum collisions leading to a denial     of service (bsc#900914)

  - CVE-2014-9512: Malicious servers could send files     outside of the transferred directory (bsc#915410)

Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

This update for rsync fixes two security issues and two non-security bugs.

The following vulnerabilities were fixed :

  - CVE-2014-8242: Checksum collisions leading to a denial     of service (bsc#900914)

  - CVE-2014-9512: Malicious servers could send files     outside of the transferred directory (bsc#915410)

The update package also includes non-security fixes. See advisory for details.

Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Michael Samuel reports :

librsync before 1.0.0 uses a truncated MD4 checksum to match blocks, which makes it easier for remote attackers to modify transmitted data via a birthday attack.

rsync was updated to fix one security issue.

This security issue was fixed :

  - CVE-2014-8242: Checksum collisions leading to a denial     of service (bsc#900914).

This non-security issue was fixed :

  - reintroduce 'use slp' directive (bsc#922710)

  - disable it by default

  - slp doesn't seem to be used much and it often caused     problems (eg boo#898513, bsc#922710)

Updated librsync packages fix security vulnerability :

librsync before 1.0.0 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 (CVE-2014-8242).

The change to fix this is not backward compatible with older versions of librsync. 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.

Also, any applications that use the librsync library will need to be recompiled against the updated library. The rdiff-backup packages have been rebuilt for this reason.

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 <miknet.net> for reporting this and     offering an initial patch.

    - Various build fixes, thanks Timothy Gu.

    - Improved rdiff man page from Debian.

    - Improved librsync.spec file for building RPMs.

    - Fixed bug #1110812 'internal error: job made no       progress'; on large files.

    - Moved hosting to https://github.com/librsync/librsync/

    - Travis-CI.org integration test at       https://travis-ci.org/librsync/librsync/

    - Remove bundled copy of popt; it must be installed       separately.

    - You can set `$LIBTOOLIZE` before running `autogen.sh`,       for example on OS X Homebrew where it is called       `glibtoolize`.

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ID	Name	Product	Family	Severity
91377	GLSA-201605-04 : rsync: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	medium
88009	SUSE SLED11 / SLES11 Security Update : rsync (SUSE-SU-2016:0176-1)	Nessus	SuSE Local Security Checks	medium
88007	SUSE SLED12 / SLES12 Security Update : rsync (SUSE-SU-2016:0173-1)	Nessus	SuSE Local Security Checks	medium
87832	FreeBSD : librsync -- collision vulnerability (b22b016b-b633-11e5-83ef-14dae9d210b8)	Nessus	FreeBSD Local Security Checks	medium
86394	openSUSE Security Update : rsync (openSUSE-2015-659)	Nessus	SuSE Local Security Checks	medium
83096	Mandriva Linux Security Advisory : librsync (MDVSA-2015:204)	Nessus	Mandriva Local Security Checks	high
81959	Fedora 21 : csync2-1.34-15.fc21 / duplicity-0.6.25-3.fc21 / librsync-1.0.0-1.fc21 / etc (2015-3497)	Nessus	Fedora Local Security Checks	medium
81958	Fedora 20 : csync2-1.34-15.fc20 / duplicity-0.6.25-3.fc20 / librsync-1.0.0-1.fc20 / etc (2015-3366)	Nessus	Fedora Local Security Checks	medium
81716	Fedora 22 : csync2-1.34-15.fc22 / duplicity-0.6.25-3.fc22 / librsync-1.0.0-1.fc22 / etc (2015-2923)	Nessus	Fedora Local Security Checks	medium

Detections

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CVE-2014-8242

critical

Tenable Plugins

medium

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high

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