FKIE_CVE-2026-29774

Vulnerability from fkie_nvd - Published: 2026-03-13 19:54 - Updated: 2026-03-17 14:51
Summary
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, a client-side heap buffer overflow occurs in the FreeRDP client's AVC420/AVC444 YUV-to-RGB conversion path due to missing horizontal bounds validation of H.264 metablock regionRects coordinates. In yuv.c, the clamp() function (line 347) only validates top/bottom against the surface/YUV height, but never checks left/right against the surface width. When avc420_yuv_to_rgb (line 67) computes destination and source pointers using rect->left, it performs unchecked pointer arithmetic that can reach far beyond the allocated surface buffer. A malicious server sends a WIRE_TO_SURFACE_PDU_1 with AVC420 codec containing a regionRects entry where left greatly exceeds the surface width (e.g., left=60000 on a 128px surface). The H.264 bitstream decodes successfully, then yuv420_process_work_callback calls avc420_yuv_to_rgb which computes pDstPoint = pDstData + rect->top * nDstStep + rect->left * 4, writing 16-byte SSE vectors 1888+ bytes past the allocated heap region. This vulnerability is fixed in 3.24.0.
Impacted products
Vendor Product Version
freerdp freerdp *

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "97FCA262-35C3-4B6B-A321-15CE780FCA20",
              "versionEndExcluding": "3.24.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, a client-side heap buffer overflow occurs in the FreeRDP client\u0027s AVC420/AVC444 YUV-to-RGB conversion path due to missing horizontal bounds validation of H.264 metablock regionRects coordinates.  In yuv.c, the clamp() function (line 347) only validates top/bottom against the surface/YUV height, but never checks left/right against the surface width. When avc420_yuv_to_rgb (line 67) computes destination and source pointers using rect-\u003eleft, it performs unchecked pointer arithmetic that can reach far beyond the allocated surface buffer. A malicious server sends a WIRE_TO_SURFACE_PDU_1 with AVC420 codec containing a regionRects entry where left greatly exceeds the surface width (e.g., left=60000 on a 128px surface). The H.264 bitstream decodes successfully, then yuv420_process_work_callback calls avc420_yuv_to_rgb which computes pDstPoint = pDstData + rect-\u003etop * nDstStep + rect-\u003eleft * 4, writing 16-byte SSE vectors 1888+ bytes past the allocated heap region. This vulnerability is fixed in 3.24.0."
    },
    {
      "lang": "es",
      "value": "FreeRDP es una implementaci\u00f3n gratuita del Protocolo de Escritorio Remoto. Antes de la 3.24.0, ocurre un desbordamiento de b\u00fafer de mont\u00f3n del lado del cliente en la ruta de conversi\u00f3n YUV a RGB AVC420/AVC444 del cliente FreeRDP debido a la falta de validaci\u00f3n de l\u00edmites horizontales de las coordenadas regionRects del metabloque H.264. En yuv.c, la funci\u00f3n clamp() (l\u00ednea 347) solo valida la parte superior/inferior contra la altura de la superficie/YUV, pero nunca verifica la izquierda/derecha contra el ancho de la superficie. Cuando avc420_yuv_to_rgb (l\u00ednea 67) calcula los punteros de destino y origen usando rect-\u0026gt;left, realiza aritm\u00e9tica de punteros sin verificar que puede ir mucho m\u00e1s all\u00e1 del b\u00fafer de superficie asignado. Un servidor malicioso env\u00eda un WIRE_TO_SURFACE_PDU_1 con c\u00f3dec AVC420 que contiene una entrada regionRects donde left excede en gran medida el ancho de la superficie (por ejemplo, left=60000 en una superficie de 128px). El flujo de bits H.264 se decodifica correctamente, luego yuv420_process_work_callback llama a avc420_yuv_to_rgb que calcula pDstPoint = pDstData + rect-\u0026gt;top * nDstStep + rect-\u0026gt;left * 4, escribiendo vectores SSE de 16 bytes 1888+ bytes m\u00e1s all\u00e1 de la regi\u00f3n de mont\u00f3n asignada. Esta vulnerabilidad se corrige en la versi\u00f3n 3.24.0."
    }
  ],
  "id": "CVE-2026-29774",
  "lastModified": "2026-03-17T14:51:38.930",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 1.4,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 8.2,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 4.2,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2026-03-13T19:54:32.890",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/FreeRDP/FreeRDP/commit/6482b7a92fff3959582cef052d1967ad6bde3738"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Exploit",
        "Patch",
        "Vendor Advisory"
      ],
      "url": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-5q35-hv9x-7794"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "tags": [
        "Exploit",
        "Patch",
        "Vendor Advisory"
      ],
      "url": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-5q35-hv9x-7794"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-787"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}


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