CVE-2024-28820

Buffer overflow in the extract_openvpn_cr function in openvpn-cr.c in openvpn-auth-ldap (aka the...

6.3 MediumFix available

Buffer overflow in the extract_openvpn_cr function in openvpn-cr.c in openvpn-auth-ldap (aka the Three Rings Auth-LDAP plugin for OpenVPN) 2.0.4 allows attackers with a valid LDAP username and who can control the challenge/response password field to pass a string with more than 14 colons into this field and cause a buffer overflow.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: Low
Integrity: Low
Availability: Low

Exploit likelihood

0.42%Up 0.4 points since Jun 28, 2024

What each source reports

CVE List Score used 6.3

Record: CVE-2024-28820
CVSS 3.1: 6.3 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
Weakness: CWE-125
Updated: 2026-11-02

EUVDEUVD-2024-25906 6.3

Record: EUVD-2024-25906
CVSS 3.1: 6.3 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
Updated: 2026-11-03

GitHub AdvisoriesGHSA-wv29-6vvq-vc4h 6.3

Buffer overflow in the extract_openvpn_cr function in openvpn-cr.c in openvpn-auth-ldap (aka the...

Record: GHSA-wv29-6vvq-vc4h
CVSS 3.1: 6.3 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
Weakness: CWE-121, CWE-125
Updated: 2026-11-02

NVD 6.3

Record: CVE-2024-28820
CVSS 3.1: 6.3 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
Weakness: CWE-125
Updated: 2026-11-02

OSVALPINE-CVE-2024-28820 6.3

Record: ALPINE-CVE-2024-28820
CVSS 3.1: 6.3 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
Updated: 2026-11-02

OSV 6.3

Record: CVE-2024-28820
CVSS 3.1: 6.3 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
Updated: 2026-11-02

OSVDEBIAN-CVE-2024-28820 6.3

Record: DEBIAN-CVE-2024-28820
CVSS 3.1: 6.3 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
Updated: 2026-11-02

OSVUBUNTU-CVE-2024-28820 6.3

Record: UBUNTU-CVE-2024-28820
CVSS 3.1: 6.3 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
Updated: 2026-11-02

Affected products

threerings openvpn-auth-ldap

Affected packages

Affected packages
Package	Affected	Fixed
`openvpn-auth-ldap` Alpine:v3.21	before 2.0.4-r7	2.0.4-r7
`openvpn-auth-ldap` Alpine:v3.22	before 2.0.4-r7	2.0.4-r7
`openvpn-auth-ldap` Alpine:v3.23	before 2.0.4-r7	2.0.4-r7
`openvpn-auth-ldap` Alpine:v3.24	before 2.0.4-r7	2.0.4-r7
`openvpn-auth-ldap` Debian:12	All versions, plus listed versions 2.0.4-32.0.4-42.0.4-5	None known
`openvpn-auth-ldap` Debian:13	before 2.0.4-4	2.0.4-4
`openvpn-auth-ldap` Debian:14	before 2.0.4-4	2.0.4-4
`openvpn-auth-ldap` Ubuntu:16.04:LTS	All versions, plus listed versions 2.0.3-6.12.0.3-6.1ubuntu0.16.04.1	None known
`openvpn-auth-ldap` Ubuntu:18.04:LTS	All versions, plus listed versions 2.0.3-6.1ubuntu12.0.3-6.1ubuntu2	None known
`openvpn-auth-ldap` Ubuntu:20.04:LTS	All versions, plus listed versions 2.0.4-1ubuntu12.0.4-1ubuntu2	None known

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Affected packages
Package	Affected	Fixed
`openvpn-auth-ldap` Ubuntu:22.04:LTS	All versions, plus listed versions 2.0.4-1ubuntu4	None known
`openvpn-auth-ldap` Ubuntu:24.04:LTS	All versions, plus listed versions 2.0.4-3build1	None known
`openvpn-auth-ldap` Ubuntu:25.10	All versions, plus listed versions 2.0.4-42.0.4-5	None known
`openvpn-auth-ldap` Ubuntu:26.10	All versions, plus listed versions 2.0.4-5build1	None known
`openvpn-auth-ldap` Ubuntu:26.04:LTS	All versions, plus listed versions 2.0.4-52.0.4-5build1	None known

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2024-28820 is a medium vulnerability (CVSS 6.3) in Threerings Openvpn-auth-ldap, published June 27, 2024. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.42%, the 36th percentile. Fixed in openvpn-auth-ldap 2.0.4-r7.