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AVideo has SSRF Protection Bypass via HTTP Redirect in Image Download Endpoints

Moderate severity GitHub Reviewed Published Mar 24, 2026 in WWBN/AVideo • Updated Apr 8, 2026

Package

composer wwbn/avideo (Composer)

Affected versions

<= 26.0

Patched versions

None

Description

Summary

isSSRFSafeURL() validates URLs against private/reserved IP ranges before fetching, but url_get_contents() follows HTTP redirects without re-validating the redirect target. An attacker can bypass SSRF protection by redirecting from a public URL to an internal target.

Root Cause

Check-time: isSSRFSafeURL() at objects/functions.php:4066 resolves the hostname and validates the IP.

Use-time: url_get_contents() at objects/functions.php:1990 calls file_get_contents() with PHP's default follow_location=1 — redirects are followed without re-validation. The wget fallback at line 2047 also follows redirects by default.

Affected endpoint: objects/aVideoEncoderReceiveImage.json.php at lines 67-68, 107-108, 135-136, 160-161:

if (isValidURL($_REQUEST['downloadURL_image']) && isSSRFSafeURL($_REQUEST['downloadURL_image'])) {
    $content = url_get_contents($_REQUEST['downloadURL_image']);

Proof of Concept

  1. Attacker sets up https://attacker.com/redir to respond with 302 Location: http://169.254.169.254/latest/meta-data/
  2. Authenticated user (with upload+edit permissions) triggers image download:
GET /objects/aVideoEncoderReceiveImage.json.php?downloadURL_image=https://attacker.com/redir&...
  1. isSSRFSafeURL() resolves attacker.com → public IP → passes validation
  2. url_get_contents() follows 302 redirect to 169.254.169.254 → SSRF

Impact

  • Cloud metadata access (AWS IMDSv1, GCP, Azure)
  • Internal network service access
  • Bypasses the existing SSRF protection that was added to prevent exactly this class of attack

Note

The curl path in url_get_contents() does NOT set CURLOPT_FOLLOWLOCATION so it is not affected. Only the file_get_contents and wget fallback paths are vulnerable.

Suggested Fix

Set follow_location to 0 in the stream context and handle redirects manually with re-validation, or add isSSRFSafeURL() check inside url_get_contents() after resolving the final URL.

References

@DanielnetoDotCom DanielnetoDotCom published to WWBN/AVideo Mar 24, 2026
Published to the GitHub Advisory Database Mar 26, 2026
Reviewed Mar 26, 2026
Published by the National Vulnerability Database Mar 27, 2026
Last updated Apr 8, 2026

Severity

Moderate

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 None
User interaction Passive
Vulnerable System Impact Metrics
Confidentiality Low
Integrity Low
Availability None
Subsequent System Impact Metrics
Confidentiality None
Integrity None
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:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/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.
(14th percentile)

Weaknesses

Server-Side Request Forgery (SSRF)

The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. Learn more on MITRE.

CVE ID

CVE-2026-33766

GHSA ID

GHSA-f359-r3pv-2phf

Source code

Credits

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