Net-SNMP: Multiple vulnerabilities

Background

Net-SNMP is a collection of tools for generating and retrieving SNMP data. The SNMPv3 protocol uses a keyed-Hash Message Authentication Code (HMAC) to verify data integrity and authenticity of SNMP messages.

Description

Wes Hardaker reported that the SNMPv3 HMAC verification relies on the client to specify the HMAC length (CVE-2008-0960). John Kortink reported a buffer overflow in the Perl bindings of Net-SNMP when processing the OCTETSTRING in an attribute value pair (AVP) received by an SNMP agent (CVE-2008-2292).

Impact

An attacker could send SNMPv3 packets to an instance of snmpd providing a valid user name and an HMAC length value of 1, and easily conduct brute-force attacks to bypass SNMP authentication. An attacker could further entice a user to connect to a malicious SNMP agent with an SNMP client using the Perl bindings, possibly resulting in the execution of arbitrary code.

Workaround

There is no known workaround at this time.

Resolution

All Net-SNMP users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=net-analyzer/net-snmp-5.4.1.1"