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Fencer Vulns
medium 5.9

CVE-2017-7521 json

OpenVPN versions before 2.4.3 and before 2.3.17 are vulnerable to remote denial-of-service due to memory exhaustion caused by memory leaks…

published 2017-06-27 9 y ago modified 2026-06-17 4 mo ago also EUVD-2017-16538

cvss
5.9
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.9%
EPSS 3.9% chance of exploitation in 30 days, percentile 90%
public exploits
0
none known

Summary

OpenVPN versions before 2.4.3 and before 2.3.17 are vulnerable to remote denial-of-service due to memory exhaustion caused by memory leaks and double-free issue in extract_x509_extension().

Patch / fix

  • openvpn Debian 14, Debian 13, Debian 12 2.4.3-1

debian advisories DEBIAN-CVE-2017-7521

  • openvpn Ubuntu 14.04 LTS 2.3.2-7ubuntu3.2
  • openvpn Ubuntu 16.04 LTS 2.3.10-1ubuntu2.1

ubuntu advisories UBUNTU-CVE-2017-7521

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • openvpn-openssl1 SLES 11-SECURITY 2.3.2-0.9.1
  • openvpn SLES for SAP 12 SP2, SLES for SAP 12 SP1, SLES for SAP 12 +6 more 2.3.8-16.17.1

suse advisories SUSE-SU-2017:1718-1SUSE-SU-2017:1635-1

  • openvpn openSUSE Tumbleweed 2.5.3-1.2

opensuse advisories openSUSE-SU-2024:11128-1

  • openvpn Arch Linux 2.4.3-1

arch linux advisories AVG-318

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-2017-7521 updated cvss 7.5

openvpn: Multiple security issues fixed in OpenVPN 2.4.3 and 2.3.17

  • 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

Exploit prediction

3.85% chance of exploitation in the next 30 days, higher than 90% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.0 5.9 CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:N/A:P

Affected products

  • OpenVPN Technologies, Inc OpenVPN

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption
  • CWE-415 Double Free
  • CWE-772 Missing Release of Resource after Effective Lifetime

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.