Medium
openvpn-auth-ldap — security advisory
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.
- Products
- openvpn-auth-ldap
- Affected versions
- 2.0.3-6.1, 2.0.3-6.1ubuntu0.16.04.1, 2.0.3-6.1ubuntu1, 2.0.3-6.1ubuntu2, 2.0.4-1ubuntu1, 2.0.4-1ubuntu2, 2.0.4-1ubuntu4, 2.0.4-3build1, 2.0.4-4, 2.0.4-5, 2.0.4-5build1
- Fixed versions
- Not specified
- CVEs
- CVE-2024-28820
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 01:13 UTC · Revision 1
Source evidence
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.
osv:UBUNTU-CVE-2024-28820
openvpn-auth-ldap
Fixed versions: Not specified
openvpn-auth-ldap
Fixed versions: Not specified
openvpn-auth-ldap
Fixed versions: Not specified
openvpn-auth-ldap
Fixed versions: Not specified
openvpn-auth-ldap
Fixed versions: Not specified
openvpn-auth-ldap
Fixed versions: Not specified
openvpn-auth-ldap
Fixed versions: Not specified
openvpn-auth-ldap
Fixed versions: Not specified
Complete source record
{
"id": "107babe0c6ee14d9ce0738198ce1c10d0e2f491ac8c8c4c0125d21770e7d912a",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2024-28820",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2024-28820",
"summary": "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.",
"evidence": "osv:UBUNTU-CVE-2024-28820",
"products": [
{
"name": {
"value": "openvpn-auth-ldap",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.0.3-6.1",
"evidence": "/affected/0/versions"
},
{
"value": "2.0.3-6.1ubuntu0.16.04.1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "openvpn-auth-ldap",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.0.3-6.1ubuntu1",
"evidence": "/affected/1/versions"
},
{
"value": "2.0.3-6.1ubuntu2",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "openvpn-auth-ldap",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.0.4-1ubuntu1",
"evidence": "/affected/2/versions"
},
{
"value": "2.0.4-1ubuntu2",
"evidence": "/affected/2/versions"
}
]
},
{
"name": {
"value": "openvpn-auth-ldap",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.0.4-1ubuntu4",
"evidence": "/affected/3/versions"
}
]
},
{
"name": {
"value": "openvpn-auth-ldap",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.0.4-3build1",
"evidence": "/affected/4/versions"
}
]
},
{
"name": {
"value": "openvpn-auth-ldap",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.0.4-4",
"evidence": "/affected/5/versions"
},
{
"value": "2.0.4-5",
"evidence": "/affected/5/versions"
}
]
},
{
"name": {
"value": "openvpn-auth-ldap",
"evidence": "/affected/6/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.0.4-5build1",
"evidence": "/affected/6/versions"
}
]
},
{
"name": {
"value": "openvpn-auth-ldap",
"evidence": "/affected/7/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.0.4-5",
"evidence": "/affected/7/versions"
},
{
"value": "2.0.4-5build1",
"evidence": "/affected/7/versions"
}
]
}
],
"severity": "medium",
"structured": {
"id": "UBUNTU-CVE-2024-28820",
"aliases": [
"UBUNTU-CVE-2024-28820"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "openvpn-auth-ldap",
"purl": "pkg:deb/ubuntu/openvpn-auth-ldap?arch=source&distro=xenial",
"ecosystem": "Ubuntu:16.04:LTS"
},
"versions": [
"2.0.3-6.1",
"2.0.3-6.1ubuntu0.16.04.1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-28820.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "openvpn-auth-ldap",
"binary_version": "2.0.3-6.1ubuntu0.16.04.1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "openvpn-auth-ldap",
"purl": "pkg:deb/ubuntu/openvpn-auth-ldap?arch=source&distro=bionic",
"ecosystem": "Ubuntu:18.04:LTS"
},
"versions": [
"2.0.3-6.1ubuntu1",
"2.0.3-6.1ubuntu2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-28820.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "openvpn-auth-ldap",
"binary_version": "2.0.3-6.1ubuntu2"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "openvpn-auth-ldap",
"purl": "pkg:deb/ubuntu/openvpn-auth-ldap?arch=source&distro=focal",
"ecosystem": "Ubuntu:20.04:LTS"
},
"versions": [
"2.0.4-1ubuntu1",
"2.0.4-1ubuntu2"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-28820.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "openvpn-auth-ldap",
"binary_version": "2.0.4-1ubuntu2"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "openvpn-auth-ldap",
"purl": "pkg:deb/ubuntu/openvpn-auth-ldap?arch=source&distro=jammy",
"ecosystem": "Ubuntu:22.04:LTS"
},
"versions": [
"2.0.4-1ubuntu4"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-28820.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "openvpn-auth-ldap",
"binary_version": "2.0.4-1ubuntu4"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "openvpn-auth-ldap",
"purl": "pkg:deb/ubuntu/openvpn-auth-ldap?arch=source&distro=noble",
"ecosystem": "Ubuntu:24.04:LTS"
},
"versions": [
"2.0.4-3build1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-28820.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "openvpn-auth-ldap",
"binary_version": "2.0.4-3build1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "openvpn-auth-ldap",
"purl": "pkg:deb/ubuntu/openvpn-auth-ldap?arch=source&distro=questing",
"ecosystem": "Ubuntu:25.10"
},
"versions": [
"2.0.4-4",
"2.0.4-5"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-28820.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "openvpn-auth-ldap",
"binary_version": "2.0.4-5"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "openvpn-auth-ldap",
"purl": "pkg:deb/ubuntu/openvpn-auth-ldap?arch=source&distro=stonking",
"ecosystem": "Ubuntu:26.10"
},
"versions": [
"2.0.4-5build1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-28820.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "openvpn-auth-ldap",
"binary_version": "2.0.4-5build1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "openvpn-auth-ldap",
"purl": "pkg:deb/ubuntu/openvpn-auth-ldap?arch=source&distro=resolute",
"ecosystem": "Ubuntu:26.04:LTS"
},
"versions": [
"2.0.4-5",
"2.0.4-5build1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2024/UBUNTU-CVE-2024-28820.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "openvpn-auth-ldap",
"binary_version": "2.0.4-5build1"
}
]
}
}
],
"modified": "2026-10-17T12:56:44.498145323Z",
"provider": "osv",
"upstream": [
"CVE-2024-28820"
],
"references": [
"https://ubuntu.com/security/CVE-2024-28820",
"https://www.cve.org/CVERecord?id=CVE-2024-28820",
"https://github.com/threerings/openvpn-auth-ldap/pull/92",
"https://github.com/threerings/openvpn-auth-ldap/tags"
]
},
"related_cves": [
{
"value": "CVE-2024-28820",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 356110,
"published_at": "2024-06-27T16:15:00+00:00"
}