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chrony: two vulnerabilities

Package(s):chrony CVE #(s):CVE-2012-4502 CVE-2012-4503
Created:August 12, 2013 Updated:September 18, 2013
Description: From the Red Hat bugzilla:

Chrony upstream has released 1.29 version correcting the following two security flaws:

* CVE-2012-4502: Buffer overflow when processing crafted command packets

When the length of the REQ_SUBNETS_ACCESSED, REQ_CLIENT_ACCESSES command requests and the RPY_SUBNETS_ACCESSED, RPY_CLIENT_ACCESSES, RPY_CLIENT_ACCESSES_BY_INDEX, RPY_MANUAL_LIST command replies is calculated, the number of items stored in the packet is not validated.

A crafted command request/reply can be used to crash the server/client. Only clients allowed by cmdallow (by default only localhost) can crash the server.

With chrony versions 1.25 and 1.26 this bug has a smaller security impact as the server requires the clients to be authenticated in order to process the subnet and client accesses commands. In 1.27 and 1.28, however, the invalid calculated length is included also in the authentication check which may cause another crash.

* CVE-2012-4503: Uninitialized data in command replies

The RPY_SUBNETS_ACCESSED and RPY_CLIENT_ACCESSES command replies can contain uninitalized data from stack when the client logging is disabled or a bad subnet is requested. These commands were never used by chronyc and they require the client to be authenticated since version 1.25.

Alerts:
Fedora FEDORA-2013-14549 2013-08-11
Fedora FEDORA-2013-14539 2013-08-15
Debian DSA-2760-1 2013-09-18

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