SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2023-27598

A specially crafted `Via` header, which is deemed correct by the parser, will pass uninitialized strings to the function `MD5StringArray` which leads to the crash.

HIGH 7.5EPSS 0.97%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.97%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

OpenSIPS is a Session Initiation Protocol (SIP) server implementation. Prior to versions 3.1.7 and 3.2.4, sending a malformed `Via` header to OpenSIPS triggers a segmentation fault when the function `calc_tag_suffix` is called. A specially crafted `Via` header, which is deemed correct by the parser, will pass uninitialized strings to the function `MD5StringArray` which leads to the crash. Abuse of this vulnerability leads to Denial of Service due to a crash. Since the uninitialized string points to memory location `0x0`, no further exploitation appears to be possible. No special network privileges are required to perform this attack, as long as the OpenSIPS configuration makes use of functions such as `sl_send_reply` or `sl_gen_totag` that trigger the vulnerable code. This issue has been fixed in versions 3.1.7 and 3.2.4.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
0.97% probability · 60th percentile
CISA KEV
Not listed
Weakness
CWE-908
Affected
opensips/opensips
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.