A vulnerability was found in ZeroMQ libzmq up to 4.2.x/4.3.0 and classified as critical. Affected by this issue is the function zmq::v2_decoder_t::size_ready of the file v2_decoder.cpp. The manipulation with an unknown input leads to a integer overflow vulnerability. Using CWE to declare the problem leads to CWE-190. The product performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control. Impacted is confidentiality, integrity, and availability. CVE summarizes:

A pointer overflow, with code execution, was discovered in ZeroMQ libzmq (aka 0MQ) 4.2.x and 4.3.x before 4.3.1. A v2_decoder.cpp zmq::v2_decoder_t::size_ready integer overflow allows an authenticated attacker to overwrite an arbitrary amount of bytes beyond the bounds of a buffer, which can be leveraged to run arbitrary code on the target system. The memory layout allows the attacker to inject OS commands into a data structure located immediately after the problematic buffer (i.e., it is not necessary to use a typical buffer-overflow exploitation technique that changes the flow of control).

The bug was discovered 01/08/2019. The weakness was released 01/13/2019 (GitHub Repository). The advisory is available at github.com. This vulnerability is handled as CVE-2019-6250 since 01/13/2019. The attack may be launched remotely. A simple authentication is necessary for exploitation. Technical details are known, but there is no available exploit.

The vulnerability was handled as a non-public zero-day exploit for at least 5 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 121167 (Debian DSA-4368-1 : zeromq3 - security update), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Debian Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 172037 (OpenSUSE Security Update for zeromq (openSUSE-SU-2019:0087-1)).

Upgrading to version 4.3.1 eliminates this vulnerability. A possible mitigation has been published 1 days after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (121167). Entries connected to this vulnerability are available at VDB-75688, VDB-137686 and VDB-177860.

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• ZeroMQ

Name

• libzmq

Version

• 4.0
• 4.1
• 4.2
• 4.3

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CPE 2.2info

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