CVE-2026-28221

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{"affected": [{"affectedData": [{"product": "wazuh", "vendor": "wazuh", "versions": [{"status": "affected", "version": ">= 4.8.0, < 4.14.4"}]}], "source": "security-advisories@github.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:wazuh:wazuh:*:*:*:*:*:*:*:*", "matchCriteriaId": "DB572FD1-FC2F-4F4E-AEF4-2B03B1725B74", "versionEndExcluding": "4.14.4", "versionStartIncluding": "4.8.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Wazuh is a free and open source platform used for threat prevention, detection, and response. From version 4.8.0 to before version 4.14.4, a stack-based buffer overflow exists in print_hex_string() in wazuh-remoted. The bug is triggered when formatting attacker-controlled bytes using sprintf(dst_buf + 2*i, \"%.2x\", src_buf[i]) on platforms where char is treated as signed and the compiled code sign-extends bytes before the variadic call. For input bytes such as 0xFF, the formatting can emit \"ffffffff\" (8 chars) instead of \"ff\" (2 chars), causing an out-of-bounds write past a fixed 2049-byte stack buffer. The vulnerable path is reachable remotely prior to any agent authentication/registration logic via TCP/1514 when an oversized length prefix causes the \u201cunexpected message (hex)\u201d diagnostic path to run. Additionally, the same unauthenticated oversized-message diagnostic path logs an attacker-controlled hex dump to /var/ossec/logs/ossec.log for each trigger, allowing remote log amplification that can degrade monitoring fidelity and consume disk/I/O. This log amplification is reachable even without triggering the sign-extension overflow (e.g., using bytes < 0x80). This issue has been patched in version 4.14.4."}, {"lang": "es", "value": "Wazuh es una plataforma de c\u00f3digo abierto y gratuita utilizada para la prevenci\u00f3n, detecci\u00f3n y respuesta a amenazas. Desde la versi\u00f3n 4.8.0 hasta antes de la versi\u00f3n 4.14.4, existe un desbordamiento de b\u00fafer basado en pila en print_hex_string() en wazuh-remoted. El error se activa al formatear bytes controlados por el atacante usando sprintf(dst_buf + 2i, \u2019%.2x\u2019, src_buf[i]) en plataformas donde char se trata como con signo y el c\u00f3digo compilado extiende el signo de los bytes antes de la llamada vari\u00e1dica. Para bytes de entrada como 0xFF, el formateo puede emitir \u2019ffffffff\u2019 (8 caracteres) en lugar de \u2019ff\u2019 (2 caracteres), causando una escritura fuera de l\u00edmites m\u00e1s all\u00e1 de un b\u00fafer de pila fijo de 2049 bytes. La ruta vulnerable es accesible de forma remota antes de cualquier l\u00f3gica de autenticaci\u00f3n/registro del agente a trav\u00e9s de TCP/1514 cuando un prefijo de longitud excesiva hace que se ejecute la ruta de diagn\u00f3stico \u2019mensaje inesperado (hex)\u2019. Adem\u00e1s, la misma ruta de diagn\u00f3stico de mensaje excesivo no autenticado registra un volcado hexadecimal controlado por el atacante en /var/ossec/logs/ossec.log por cada activaci\u00f3n, lo que permite la amplificaci\u00f3n remota de registros que puede degradar la fidelidad del monitoreo y consumir disco/E/S. Esta amplificaci\u00f3n de registros es accesible incluso sin activar el desbordamiento por extensi\u00f3n de signo (p. ej., usando bytes menor que 0x80). Este problema ha sido parcheado en la versi\u00f3n 4.14.4."}], "id": "CVE-2026-28221", "lastModified": "2026-11-11T21:10:00.200", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 6.5, "baseSeverity": "MEDIUM", "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:L", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 2.5, "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"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-28221", "options": [{"exploitation": "poc"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-04-29T18:34:55.716001Z", "version": "2.0.3"}}]}, "published": "2026-04-29T19:16:23.047", "references": [{"source": "security-advisories@github.com", "tags": ["Release Notes"], "url": "https://github.com/wazuh/wazuh/releases/tag/v4.14.4"}, {"source": "security-advisories@github.com", "tags": ["Exploit", "Vendor Advisory"], "url": "https://github.com/wazuh/wazuh/security/advisories/GHSA-q9vv-7w4c-f4cm"}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Vendor Advisory"], "url": "https://github.com/wazuh/wazuh/security/advisories/GHSA-q9vv-7w4c-f4cm"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-121"}, {"lang": "en", "value": "CWE-400"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

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