CVE-2023-28099 [Medium] | Input Validation Bypass in Opensips

OpenSIPS is a Session Initiation Protocol (SIP) server implementation. Prior to versions 3.1.9 and 3.2.6, if `ds_is_in_list()` is used with an invalid IP address string (`NULL` is illegal input), OpenSIPS will attempt to print a string from a random address (stack garbage), which could lead to a crash. All users of `ds_is_in_list()` without the `$si` variable as 1st parameter could be affected by this vulnerability to a larger, lesser or no extent at all, depending if the data passed to the function is a valid IPv4 or IPv6 address string or not. Fixes will are available starting with the 3.1.9 and 3.2.6 minor releases. There are no known workarounds.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.39%	0.91%	+0.52%
2	2026-03-17	0.08%	0.39%	+0.31%
3	2025-11-21	—	0.08%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.39%

0.91%

+0.52%

2026-03-17

0.08%

0.39%

+0.31%

2025-11-21

—

0.08%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
5.9	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:H/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:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. 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.	2.2	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]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

5.9

3.1

MEDIUM

CVSS:3.1/AV:N/AC:H/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:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
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.

2.2

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]

OS Trackers for CVE-2023-28099

vendor	priority	summary	link
`ubuntu`	medium	CVE-2023-28099 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-2023-28099

Affected software / configurations for CVE-2023-28099

Vendor	Product	Version	Raw CPE
opensips	opensips	< 3.1.9	cpe:2.3:a:opensips:opensips::::::::
opensips	opensips	>= 3.2.0, < 3.2.6	cpe:2.3:a:opensips:opensips::::::::

References for CVE-2023-28099

URL	Tags
https://github.com/OpenSIPS/opensips/commit/e2f13d374	Patch Third Party Advisory
https://github.com/OpenSIPS/opensips/issues/2780	Third Party Advisory
https://github.com/OpenSIPS/opensips/security/advisories/GHSA-pfm5-6vhv-3ff3	Third Party Advisory

URL

CVE-2023-28099 | OpenSIPS has vulnerability in the ds_is_in_list() function

Exploit prediction scoring system (EPSS) score for CVE-2023-28099

Common vulnerability scoring system (CVSS) metrics for CVE-2023-28099

Weakness enumeration for CVE-2023-28099

OS Trackers for CVE-2023-28099

Affected software / configurations for CVE-2023-28099

References for CVE-2023-28099