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Fencer Vulns
medium 6.3

CVE-2024-28820 json

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)…

published 2024-06-27 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-25906

cvss
6.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 36%
public exploits
0
none known

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.

Patch / fix

  • openvpn-auth-ldap Debian 14, Debian 13 2.0.4-4

debian advisories DEBIAN-CVE-2024-28820

  • openvpn-auth-ldap Alpine 3.24, Alpine 3.23, Alpine 3.22 +1 more 2.0.4-r7

alpine advisories ALPINE-CVE-2024-28820

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2024-28820 updated

openvpn-auth-ldap: buffer overflow

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.42% chance of exploitation in the next 30 days, higher than 36% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 6.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
CNA 3.1 6.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

Affected products

  • threerings openvpn-auth-ldap

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.