CVE-2023-27600 : What You Need to Know

This article provides detailed insights into CVE-2023-27600, a vulnerability found in OpenSIPS related to its codec_delete_XX() functions.

Understanding CVE-2023-27600

The CVE-2023-27600 vulnerability pertains to OpenSIPS, a Session Initiation Protocol (SIP) server implementation. The issue arises in versions prior to 3.1.7 and 3.2.4, where OpenSIPS crashes upon receiving a malformed SDP body and processing it through the

delete_sdp_line

function in the sipmsgops module. This vulnerability can be exploited by supplying an SDP body that lacks a line feed (

\n

) termination.

What is CVE-2023-27600?

The vulnerability in OpenSIPS allows attackers to crash the server by sending malicious input that triggers a crash in the

delete_sdp_line

function. The issue impacts configurations utilizing functions like

codec_delete_except_re

, leading to a Denial of Service vulnerability due to an

abort

in the lumps processing function.

The Impact of CVE-2023-27600

Exploitation of CVE-2023-27600 can result in a server crash, affecting the availability of the OpenSIPS server. Attackers can abuse this vulnerability to disrupt services relying on the affected functions, ultimately leading to a Denial of Service situation.

Technical Details of CVE-2023-27600

The vulnerability in OpenSIPS has been categorized with a CVSS v3.1 base score of 7.5, indicating a high severity issue. It has been classified with an attack complexity of "LOW," attack vector as "NETWORK," and high availability impact.

Vulnerability Description

The vulnerability in OpenSIPS originates from improper input validation, specifically within the

delete_sdp_line

function, leading to a server crash when processing malformed SDP bodies.

Affected Systems and Versions

OpenSIPS versions prior to 3.1.7 and 3.2.4 are impacted by CVE-2023-27600. Systems utilizing functions such as

codec_delete_except_re

are susceptible to exploitation.

Exploitation Mechanism

Exploiting CVE-2023-27600 involves sending a malformed SDP body lacking a line feed (

\n

) termination, triggering a crash in the

delete_sdp_line

function, ultimately disrupting server operations.

Mitigation and Prevention

To safeguard systems against CVE-2023-27600, immediate steps need to be taken to address the vulnerability and prevent potential exploitation.

Immediate Steps to Take

It is crucial to update OpenSIPS to versions 3.1.7 or 3.2.4, where the vulnerability has been patched. This will mitigate the risk of server crashes and Denial of Service incidents stemming from the vulnerability.

Long-Term Security Practices

Implementing proper input validation mechanisms and conducting regular security assessments can help prevent similar vulnerabilities from arising in the future. Training staff on secure coding practices is also essential for maintaining system security.

Patching and Updates

Regularly monitoring security advisories from OpenSIPS and promptly applying patches and updates is vital to stay protected against emerging vulnerabilities. Keeping the software up to date ensures that known security issues are addressed promptly.