CVE-2023-28095 | OpenSIPS has vulnerability in the building the local negative replies

OpenSIPS is a Session Initiation Protocol (SIP) server implementation. Versions prior to 3.1.7 and 3.2.4 have a potential issue in `msg_translator.c:2628` which might lead to a server crash. This issue was found while fuzzing the function `build_res_buf_from_sip_req` but could not be reproduced against a running instance of OpenSIPS. This issue could not be exploited against a running instance of OpenSIPS since no public function was found to make use of this vulnerable code. Even in the case of exploitation through unknown vectors, it is highly unlikely that this issue would lead to anything other than Denial of Service. This issue has been fixed in versions 3.1.7 and 3.2.4.

Published: 2023-03-15 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2023-28095 is rated Moderate Risk (50.3/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.97%). Mandatory action: 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-2023-28095

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 2026-06-15 0.70% 0.97% +0.27%
2 2026-03-17 0.28% 0.70% +0.42%
3 2025-12-08 0.28%

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-28095

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-2023-28095

OS Trackers for CVE-2023-28095

vendor priority summary link
ubuntu low CVE-2023-28095 low 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-2023-28095

Affected software / configurations for CVE-2023-28095

Vendor Product Version Raw CPE
opensips opensips < 3.1.7 cpe:2.3:a:opensips:opensips:*:*:*:*:*:*:*:*
opensips opensips >= 3.2.0, < 3.2.4 cpe:2.3:a:opensips:opensips:*:*:*:*:*:*:*:*

References for CVE-2023-28095

cvelogic Threat Intelligence