VulnerabilityPublished 27 Jun 2025

CVE-2025-6776: xiaoyunjie openvpn-cms-flask · Path Traversal

Affects xiaoyunjie openvpn-cms-flaskSource CVE Database V5

Public exploit available · CVSS 6.9 Medium.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 4.0 base score

6.9Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.7% chance of exploitation in 30 days – higher than 54% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P

Base metrics

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: Low
Vulnerable system integrity: Low
Vulnerable system availability: Low
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Threat metrics

Exploit Maturity: POC

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Vulnerable System.
Vulnerable system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Vulnerable System.
Vulnerable system availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the Vulnerable System are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.
Exploit Maturity: POC: Based on threat intelligence sources each of the following must apply: · Proof-of-concept is publicly available · No knowledge of reported attempts to exploit this vulnerability · No knowledge of publicly available solutions used to simplify attempts to exploit the vulnerability

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 27 Jun 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
CVSS exploit maturity: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
GitHubxiaoyunjie/openvpn-cms-flask`pkg:github/xiaoyunjie/openvpn-cms-flask`Other threats	Affected 1.2.0 – 1.2.7 8 affected builds	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

European organizations should immediately upgrade openvpn-cms-flask to version 1.2.8 or later to apply the official patch. In addition to patching, organizations should implement strict input validation and sanitization on file upload parameters to prevent path traversal attempts. Deploying web application firewalls (WAFs) with rules tuned to detect and block path traversal payloads targeting the 'image' parameter can provide an additional layer of defense. Regularly audit and monitor file system access logs for unusual file access patterns or unauthorized file modifications. Restrict file system permissions for the application user to the minimum necessary, preventing access to sensitive directories outside the upload folder. Network segmentation should isolate VPN management interfaces from general user networks to limit exposure. Finally, conduct vulnerability scanning and penetration testing focused on file upload functionalities to proactively identify similar weaknesses.

Description

A vulnerability classified as critical was found in xiaoyunjie openvpn-cms-flask up to 1.2.7. This vulnerability affects the function Upload of the file app/plugins/oss/app/controller.py of the component File Upload. The manipulation of the argument image leads to path traversal. The attack can be initiated remotely. The exploit has been disclosed to the public and may be used. Upgrading to version 1.2.8 is able to address this issue. The name of the patch is e23559b98c8ea2957f09978c29f4e512ba789eb6. It is recommended to upgrade the affected component.

Impact

For European organizations, the impact of CVE-2025-6776 can be significant depending on the deployment scale of openvpn-cms-flask. As this product is related to OpenVPN management via a Flask-based CMS, it is likely used in network infrastructure or VPN management contexts. Exploitation could allow attackers to access or modify sensitive configuration files, credentials, or other critical data stored on the server, potentially leading to unauthorized network access or disruption of VPN services. This could compromise confidentiality of internal communications and integrity of VPN configurations. Availability impact is possible if critical files are overwritten or deleted. Given the remote, unauthenticated exploit vector, attackers could leverage this vulnerability to gain footholds in corporate networks, especially in sectors relying heavily on VPNs for secure remote access, such as finance, healthcare, and government institutions in Europe. The medium CVSS score suggests moderate but non-trivial risk, emphasizing the need for timely patching to prevent lateral movement or data breaches.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 27 Jun 2025, 20:24 UTC

Technical details

References

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