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Vulnerability of Dnsmasq: information disclosure via tcp_request

Synthesis of the vulnerability 

A local attacker can read a memory fragment of Dnsmasq, in order to obtain sensitive information; and maybe make the server halt.
Impacted systems: Arkoon FAST360, Debian, Dnsmasq, openSUSE, Solaris, SUSE Linux Enterprise Desktop, SLES, Ubuntu.
Severity of this alert: 2/4.
Creation date: 17/04/2015.
Références of this alert: bulletinjul2015, CVE-2015-3294, DSA-3251-1, DSA-3251-2, openSUSE-SU-2015:0857-1, OSI-1502, STORM-2015-09-EN, STORM-2015-10-EN, STORM-2015-11-EN.2, STORM-2015-12-EN, SUSE-SU-2017:2616-1, SUSE-SU-2017:2617-1, SUSE-SU-2017:2619-1, USN-2593-1, VIGILANCE-VUL-16649.

Description of the vulnerability 

The Dnsmasq includes a DNS cache.

The routine tcp_request() builds the response packet. However, the function "setup_reply" does not take into account some possible errors while evaluating the response size. Such an error would make the server return uninitialized data from the process heap and maybe reference an invalid address, and then make the server process be killed.

A local attacker can therefore read a memory fragment of Dnsmasq, in order to obtain sensitive information; and maybe make the server halt.
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This vulnerability note impacts software or systems such as Arkoon FAST360, Debian, Dnsmasq, openSUSE, Solaris, SUSE Linux Enterprise Desktop, SLES, Ubuntu.

Our Vigil@nce team determined that the severity of this cybersecurity vulnerability is medium.

The trust level is of type confirmed by the editor, with an origin of internet client.

An attacker with a expert ability can exploit this computer threat note.

Solutions for this threat 

Dnsmasq: version 2.73rc4.
The version 2.73rc4 is fixed:
  http://www.thekelleys.org.uk/dnsmasq/

Dnsmasq: patch for tcp_request.
A patch is available in information sources.

Arkoon Fast360: version 5.0/35.
The version 5.0/35 is fixed.

Debian: new dnsmasq packages.
New packages are available:
  Debian 7: dnsmasq 2.62-3+deb7u3
  Debian 8: dnsmasq 2.72-3+deb8u1

openSUSE: new dnsmasq packages.
New packages are available:
  openSUSE 13.1: dnsmasq 2.65-7.3.1
  openSUSE 13.2: dnsmasq 2.71-3.4.1

Solaris: patch for Third Party (07/2015).
A patch is available:
  https://support.oracle.com/rs?type=doc&id=1448883.1

SUSE LE: new dnsmasq packages (03/10/2017).
New packages are available:
  SUSE LE 11 SP3: dnsmasq 2.78-0.16.5.1
  SUSE LE 11 SP4: dnsmasq 2.78-0.17.5.1
  SUSE LE 12 RTM: dnsmasq 2.78-6.6.1

Ubuntu: new dnsmasq packages.
New packages are available:
  Ubuntu 15.04: dnsmasq 2.72-3ubuntu0.1
  Ubuntu 14.10: dnsmasq 2.71-1ubuntu0.1
  Ubuntu 14.04 LTS: dnsmasq 2.68-1ubuntu0.1
  Ubuntu 12.04 LTS: dnsmasq 2.59-4ubuntu0.2
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