A vulnerability has been reported in Net-SNMP, which can be exploited by malicious people to spoof authenticated SNMPv3 packets.

A vulnerability has been reported in Net-SNMP, which can be exploited by malicious people to spoof authenticated SNMPv3 packets.

The vulnerability is caused due to an error within the verification of the HMAC digest. This can be exploited to increase the chance of successfully spoofing a packet to 1 in 256 by sending a specially crafted SNMPv3 packet with an incomplete 1 byte HMAC digest.

Successful exploitation requires a valid username.

The vulnerability is reported in versions prior to 5.4.1.1 of the 5.4.x branch, 5.3.2.1 of the 5.3.x branch, and 5.2.4.1 of the 5.2.x branch.

Update to version 5.4.1.1, 5.3.2.1, or 5.2.4.1.