OpenVPN version 2.6.1 through 2.6.13 in server mode using TLS-crypt-v2 allows remote attackers to trigger a denial of service by corrupting and replaying network packets in the early handshake phase

There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:

  - OpenVPN version 2.6.1 through 2.6.13 in server mode using TLS-crypt-v2 allows remote attackers to trigger
    a denial of service by corrupting and replaying network packets in the early handshake phase
    (CVE-2025-2704)

  - Improper validation of source IP addresses in OpenVPN version 2.6.0 through 2.6.15 and 2.7_alpha1 through
    2.7_rc1 allows an attacker to open a session from a different IP address which did not initiate the
    connection resulting in a denial of service for the originating client (CVE-2025-13086)

The version of Tencent Linux installed on the remote TencentOS Server 4 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the TSSA-2025:0278 advisory.

    Package updates are available for TencentOS Server 4 that fix the following vulnerabilities:

    CVE-2025-2704:
    OpenVPN version 2.6.1 through 2.6.13 in server mode using TLS-crypt-v2 allows remote attackers to trigger     a denial of service by corrupting and replaying network packets in the early handshake phase

Tenable has extracted the preceding description block directly from the Tencent Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 host has packages installed that are affected by a vulnerability as referenced in the SUSE-SU-2025:01508-1 advisory.

    - CVE-2025-2704: Fixed remote DoS due to possible ASSERT() on OpenVPN servers using --tls-crypt-v2     (bsc#1240392)

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

It is, therefore, affected by a vulnerability as referenced in the ALAS2023-2025-967 advisory.

    OpenVPN version 2.6.1 through 2.6.13 in server mode using TLS-crypt-v2 allows remote attackers to trigger     a denial of service by corrupting and replaying network packets in the early handshake phase     (CVE-2025-2704)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 / openSUSE 15 host has packages installed that are affected by a vulnerability as referenced in the SUSE-SU-2025:1508-1 advisory.

    - CVE-2025-2704: Fixed remote DoS due to possible ASSERT() on OpenVPN servers using --tls-crypt-v2     (bsc#1240392)

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Fedora 40 host has a package installed that is affected by a vulnerability as referenced in the FEDORA-2025-3711fce03c advisory.

    Update to upstream OpenVPN 2.6.14     Fixes CVE-2025-2704


Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - OpenVPN version 2.6.1 through 2.6.13 in server mode using TLS-crypt-v2 allows remote attackers to trigger
    a denial of service by corrupting and replaying network packets in the early handshake phase
    (CVE-2025-2704)

The remote Fedora 41 host has a package installed that is affected by a vulnerability as referenced in the FEDORA-2025-277b5e1d96 advisory.

    Update to upstream OpenVPN 2.6.14     Fixes CVE-2025-2704


Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

OpenVPN from 2.6.1 through 2.6.13, setup with tls-crypt-v2. is affected by a denial of service vulnerability.  A local attacker who can monitor network traffic, can inject specially crafted packets during the tls-crypt2-v2 handshake and corrupt the server.

The remote Ubuntu 24.04 LTS / 24.10 host has a package installed that is affected by a vulnerability as referenced in the USN-7411-1 advisory.

    It was discovered that OpenVPN incorrectly handled certain malformed packets. A remote attacker could     possibly use this issue to cause OpenVPN to crash, resulting in a denial of service.

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The version of FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the 2cad4541-0f5b-11f0-89f8-411aefea0df9 advisory.

    Gert Doering reports:
    OpenVPN servers between 2.6.1 and 2.6.13 using
                --tls-crypt-v2 can be made to abort with an ASSERT() message by                 sending a particular combination of authenticated and malformed packets.
    To trigger the bug, a valid tls-crypt-v2 client key is needed, or                 network observation of a handshake with a valid tls-crypt-v2 client key     No crypto integrity is violated, no data is leaked, and no remote                 code execution is possible.
    This bug does not affect OpenVPN clients.

Tenable has extracted the preceding description block directly from the FreeBSD security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
436127	Alpine: multiple openvpn packages: security update to 2.6.16-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	high
436127	Alpine: multiple openvpn packages: security update to 2.6.16-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	high
276223	TencentOS Server 4: openvpn (TSSA-2025:0278)	Nessus	Tencent Local Security Checks	high
237924	SUSE SLED15 / SLES15 Security Update : openvpn (SUSE-SU-2025:01508-1)	Nessus	SuSE Local Security Checks	high
235903	Amazon Linux 2023 : openvpn, openvpn-devel (ALAS2023-2025-967)	Nessus	Amazon Linux Local Security Checks	high
235631	SUSE SLED15: openvpn / openvpn-auth-pam-plugin / openvpn-dco / openvpn-dco-devel / etc (SUSE-SU-2025:1508-1)	Nessus	SuSE Local Security Checks	high
234186	Fedora 40 : openvpn (2025-3711fce03c)	Nessus	Fedora Local Security Checks	high
424801	Alpine: multiple openvpn packages: security update to 2.6.14-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	high
424801	Alpine: multiple openvpn packages: security update to 2.6.14-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	high
233986	Fedora 41 : openvpn (2025-277b5e1d96)	Nessus	Fedora Local Security Checks	high
233860	OpenVPN Server versions 2.6.1 <= 2.6.13 DoS	Nessus	Windows	high
233827	Ubuntu 24.04 LTS / 24.10 : OpenVPN vulnerability (USN-7411-1)	Nessus	Ubuntu Local Security Checks	high
233819	FreeBSD : openvpn -- server-side denial-of-service vulnerability with tls-crypt-v2 (2cad4541-0f5b-11f0-89f8-411aefea0df9)	Nessus	FreeBSD Local Security Checks	high

Detections

Analytics

CVE-2025-2704

high

Tenable Plugins

high

high

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