GHSA-J9WJ-M24M-7JJ6

Vulnerability from github – Published: 2025-11-26 22:09 – Updated: 2025-12-01 16:06

Summary

willitmerge has a Command Injection vulnerability

Details

willitmerge describes itself as a command line tool to check if pull requests are mergeable. There is a Command Injection vulnerability in version willitmerge@0.2.1.

Resources: * Project's GitHub source code: https://github.com/shama/willitmerge/ * Project's npm package: https://www.npmjs.com/package/willitmerge

Background on exploitation

Reporting a Command Injection vulnerability in willitmerge npm package.

A security vulnerability manifests in this package due to the use of insecure child process execution API (exec) to which it concateanes user input, whether provided to the command-line flag, or is in user control in the target repository.

Exploit

POC 1

Install willitmerge
Run it with the following command

willitmerge --verbose --remote "https://github.com/lirantal/npq.git; touch /tmp/hel"

Confirm the file /tmp/hel is created on disk

GitHub-sourced attack vector

Lines 189-197 in lib/willitmerge.js pass user input controlled by repository collaborators into the git command:

  var cmds = [
    'git checkout -b ' + branch + ' ' + that.options.remote + '/' + iss.base.ref,
    'git remote add ' + branch + ' ' + gitUrl,
    'git pull ' + branch + ' ' + iss.head.ref,
    'git reset --merge HEAD',
    'git checkout ' + origBranch,
    'git branch -D ' + branch,
    'git remote rm ' + branch
  ];

Users creating malicious branch names such as ;{echo,hello,world}>/tmp/c

This is a similar attack vector to that which was reported for the [pullit vulnerability (https://security.snyk.io/vuln/npm:pullit:20180214)

Author

Liran Tal

Severity

6.9 (Medium)


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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "willitmerge"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "0.2.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2025-66219"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-77"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2025-11-26T22:09:27Z",
    "nvd_published_at": "2025-11-29T02:15:52Z",
    "severity": "MODERATE"
  },
  "details": "willitmerge describes itself as a command line tool to check if pull requests are mergeable. There is a Command Injection vulnerability in version `willitmerge@0.2.1`.\n\nResources: \n * Project\u0027s GitHub source code: https://github.com/shama/willitmerge/\n * Project\u0027s npm package: https://www.npmjs.com/package/willitmerge\n\n## Background on exploitation\n\nReporting a Command Injection vulnerability in `willitmerge` npm package.\n\nA security vulnerability manifests in this package due to the use of insecure child process execution API (`exec`) to which it concateanes user input, whether provided to the command-line flag, or is in user control in the target repository.\n\n## Exploit \n\n### POC 1\n\n1. Install `willitmerge`\n2. Run it with the following command\n\n```sh\nwillitmerge --verbose --remote \"https://github.com/lirantal/npq.git; touch /tmp/hel\"\n```\n\n3. Confirm the file `/tmp/hel` is created on disk\n\n### GitHub-sourced attack vector\n\n[Lines 189-197](https://github.com/shama/willitmerge/blob/2fe91d05191fb05ac6da685828d109a3a5885028/lib/willitmerge.js#L189-L197) in `lib/willitmerge.js`\npass user input controlled by repository collaborators into the git command:\n\n```js\n  var cmds = [\n    \u0027git checkout -b \u0027 + branch + \u0027 \u0027 + that.options.remote + \u0027/\u0027 + iss.base.ref,\n    \u0027git remote add \u0027 + branch + \u0027 \u0027 + gitUrl,\n    \u0027git pull \u0027 + branch + \u0027 \u0027 + iss.head.ref,\n    \u0027git reset --merge HEAD\u0027,\n    \u0027git checkout \u0027 + origBranch,\n    \u0027git branch -D \u0027 + branch,\n    \u0027git remote rm \u0027 + branch\n  ];\n```\n\nUsers creating malicious branch names such as `;{echo,hello,world}\u003e/tmp/c`\n\nThis is a similar attack vector to that which was reported for the [pullit vulnerability (https://security.snyk.io/vuln/npm:pullit:20180214)\n\n# Author\n\nLiran Tal",
  "id": "GHSA-j9wj-m24m-7jj6",
  "modified": "2025-12-01T16:06:54Z",
  "published": "2025-11-26T22:09:27Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/shama/willitmerge/security/advisories/GHSA-j9wj-m24m-7jj6"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-66219"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/shama/willitmerge"
    },
    {
      "type": "WEB",
      "url": "https://github.com/shama/willitmerge/blob/2fe91d05191fb05ac6da685828d109a3a5885028/lib/willitmerge.js#L189-L197"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ],
  "summary": "willitmerge has a Command Injection vulnerability"
}

CVE-2025-66219 (GCVE-0-2025-66219)

Vulnerability from cvelistv5 – Published: 2025-11-29 01:34 – Updated: 2025-12-01 19:15

Title

willitmerge has a command Injection vulnerability

Summary

willitmerge is a command line tool to check if pull requests are mergeable. In versions 0.2.1 and prior, there is a command Injection vulnerability in willitmerge. The vulnerability manifests in this package due to the use of insecure child process execution API (exec) to which it concatenates user input, whether provided to the command-line flag, or is in user control in the target repository. At time of publication, no known fix is public.

Severity

6.9 (Medium)


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

SSVC

Exploitation: poc Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2025-12-01 18:43 UTC

CWE

CWE-77 - Improper Neutralization of Special Elements used in a Command ('Command Injection')

Assigner

GitHub_M mitre root Scorecard

References

2 references

URL	Tags
https://github.com/shama/willitmerge/security/adv…	x_refsource_CONFIRM
https://github.com/shama/willitmerge/blob/2fe91d0…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
shama	willitmerge	Affected: <= 0.2.1

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2025-66219",
                "options": [
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                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-12-01T18:43:43.662991Z",
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          "shortName": "CISA-ADP"
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            "tags": [
              "exploit"
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            "url": "https://github.com/shama/willitmerge/security/advisories/GHSA-j9wj-m24m-7jj6"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
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          "product": "willitmerge",
          "vendor": "shama",
          "versions": [
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              "status": "affected",
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            }
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      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "willitmerge is a command line tool to check if pull requests are mergeable. In versions 0.2.1 and prior, there is a command Injection vulnerability in willitmerge. The vulnerability manifests in this package due to the use of insecure child process execution API (exec) to which it concatenates user input, whether provided to the command-line flag, or is in user control in the target repository. At time of publication, no known fix is public."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 6.9,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
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            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "LOW"
          }
        }
      ],
      "problemTypes": [
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      "providerMetadata": {
        "dateUpdated": "2025-11-29T01:34:33.487Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
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      "title": "willitmerge has a command Injection vulnerability"
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  "cveMetadata": {
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    "dateReserved": "2025-11-24T23:01:29.679Z",
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    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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