CVE-2023-27596 | OpenSIPS has vulnerability in the codec_delete_XX() functions

OpenSIPS is a Session Initiation Protocol (SIP) server implementation. Prior to versions 3.1.8 and 3.2.5, OpenSIPS crashes when a malformed SDP body is sent multiple times to an OpenSIPS configuration that makes use of the `stream_process` function. This issue was discovered during coverage guided fuzzing of the function `codec_delete_except_re`. By abusing this vulnerability, an attacker is able to crash the server. It affects configurations containing functions that rely on the affected code, such as the function `codec_delete_except_re`. This issue has been fixed in version 3.1.8 and 3.2.5.

Published: 2023-03-15 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-27596 is rated Moderate Risk (49/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.32%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-27596

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-17 0.39% 0.32% -0.07%
2 2026-03-16 0.07% 0.39% +0.32%
3 2025-11-21 — 0.07% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-27596

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2023-27596

OS Trackers for CVE-2023-27596

vendor priority summary link
ubuntu medium CVE-2023-27596 medium priority: Ubuntu including 1 source packages (opensips), 7 status rows across 7 suites (bionic, focal, jammy, kinetic, trusty, upstream, xenial): DNE 3, ignored 2, needs-triage 2. https://ubuntu.com/security/CVE-2023-27596

Affected software / configurations for CVE-2023-27596

Vendor Product Version Raw CPE
opensips opensips < 3.1.8 cpe:2.3:a:opensips:opensips:*:*:*:*:*:*:*:*
opensips opensips >= 3.2.0, < 3.2.5 cpe:2.3:a:opensips:opensips:*:*:*:*:*:*:*:*

References for CVE-2023-27596

cvelogic Threat Intelligence