Versions of the package ssrfcheck before 1.2.0 are vulnerable to Server-Side Request Forgery (SSRF) due to an incomplete denylist of IP address ranges. Specifically, the package fails to classify the reserved IP address space 224.0.0.0/4 (Multicast) as invalid. This oversight allows attackers to craft requests targeting these multicast addresses.
Versions of the package ssrfcheck before 1.2.0 are vulnerable to Server-Side Request Forgery (SSRF) due to an incomplete denylist of IP address ranges. Specifically, the package fails to classify the reserved IP address space 224.0.0.0/4 (Multicast) as invalid. This oversight allows attackers to craft requests targeting these multicast addresses.
Versions of the package ssrfcheck before 1.2.0 are vulnerable to Server-Side Request Forgery (SSRF) due to an incomplete denylist of IP address ranges. Specifically, the package fails to classify the reserved IP address space 224.0.0.0/4 (Multicast) as invalid. This oversight allows attackers to craft requests targeting these multicast addresses.
### Duplicate Advisory
This advisory has been withdrawn because it is a duplicate of GHSA-p4hc-9pjh-55c8. This link is maintained to preserve external references.
### Original Description
Versions of the package ssrfcheck below 1.2.0 are vulnerable to Server-Side Request Forgery (SSRF) due to an incomplete denylist of IP address ranges. Specifically, the package fails to classify the reserved IP address space 224.0.0.0/4 (Multicast) as invalid. This oversight allows attackers to craft requests targeting these multicast addresses.
# SSRF Bypass in `ssrfcheck` - fails to classify reserved IP address space as invalid
`ssrfcheck` is an npm package that serves to provide protection from SSRF by validating URLs or hostname inputs.
Resources:
* Project's GitHub code repository: https://github.com/felippe-regazio/ssrfcheck
* Project's npm package: https://www.npmjs.com/package/ssrfcheck
## Vulnerability
The `ssrfcheck` package maintains a denylist of IP addresses and ranges to check against when validating if an IP address is to be considered as safe or not.
However, the IP address list used for the denylist is incomplete and misses a reserved IP address space as defined by the IANA (Internet Assigned Numbers Authority):
- 224.0.0.0/4 - Multicast
Practically, this reserved IP address space is used for multicast traffic and would most commonly be used for reserved local communication over network protocols such as UDP, which would make it less likely to be used in a typical SSRF attack in practice.
However, such reserved IP address space shouldn't be allowed and it would be responsible of the SSRF protection package to align and conform to an agreed-upon standard of special-purposed addresses that should not be considered a valid public IP address. For reference, the popular npm packages `private-ip` and `ipaddr.js` that are highly dependent-upon to make decisions about SSRF protection and both consider the above mentioned IP address space as reserved and is not considered a valid public IP address.
## Exploit Proof of Concept
1. Install the `ssrfcheck` package:
```bash
npm install ssrfcheck
```
2. Define an `app.js` file with the programmatic API of `ssrfcheck`:
```javascript
import { isSSRFSafeURL } from 'ssrfcheck';
let result
result = isSSRFSafeURL('https://012.1.2.3/whatever');
console.log(result); // returns false
result = isSSRFSafeURL('https://localhost:8080/whatever');
console.log(result); // returns false
result = isSSRFSafeURL('https://239.255.255.250:8080/whatever');
console.log(result); // returns true - bypassed
```
## Vulnerable versions
All versions of ssrfcheck are vulnerable to this issue, up to and including to the latest version of `1.1.1`.
## Assigned CVE
[CVE-2025-8267](https://nvd.nist.gov/vuln/detail/CVE-2025-8267)
# Author
Liran Tal
EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.
Original publisher date fields
datePublished: Jul 28, 2025, 5:00:00 AM
dateUpdated: Jul 28, 2025, 4:01:35 PM
No normalized affected-package data is projected for this source revision. The original publisher record may contain additional product and version evidence; this does not establish that a package is unaffected.
NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.
The original JSON retains the logical configuration operators, exclusions and version bounds.
No normalized affected-package data is projected for this source revision. The original publisher record may contain additional product and version evidence; this does not establish that a package is unaffected.