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    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-64620",
        "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "state": "PUBLISHED",
        "assignerShortName": "VulnCheck",
        "dateReserved": "2026-07-20T11:58:54.524Z",
        "datePublished": "2026-07-20T12:04:53.105Z",
        "dateUpdated": "2026-07-21T11:08:25.119Z"
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                "dateUpdated": "2026-07-21T11:08:25.119Z"
            },
            "datePublic": "2026-07-06T00:00:00.000Z",
            "title": "FreeRDP before 3.28.0 Heap Buffer Overflow via crypto_rsa_common",
            "descriptions": [
                {
                    "lang": "en",
                    "value": "FreeRDP before 3.28.0 (affected <=3.27.1) contains a heap-based buffer overflow in crypto_rsa_common() (libfreerdp/crypto/crypto.c). The function writes the modular-exponentiation result into the caller's output buffer via BN_bn2bin() and only afterward checks output_length > out_length, so out-of-bounds bytes are written before the bounds check. On the server side, when a client selects RDP Standard Security, the encrypted client random is decrypted into a fixed 32-byte buffer. Because the server publishes its RSA public key, an unauthenticated attacker can forge a ciphertext whose decrypted value is up to the full modulus length (e.g. 256 bytes for RSA-2048), overflowing the 32-byte heap buffer by up to ~224 attacker-controlled bytes pre-authentication, resulting in denial of service."
                }
            ],
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "lang": "en",
                            "description": "Heap-based Buffer Overflow",
                            "cweId": "CWE-122",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "vendor": "FreeRDP",
                    "product": "FreeRDP",
                    "defaultStatus": "unaffected",
                    "versions": [
                        {
                            "version": "0",
                            "status": "affected",
                            "versionType": "semver",
                            "lessThan": "3.28.0"
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                            "version": "3.28.0",
                            "status": "unaffected",
                            "versionType": "semver"
                        }
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                            "negate": false,
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                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*",
                                    "versionEndExcluding": "3.28.0"
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            ],
            "metrics": [
                {
                    "cvssV4_0": {
                        "Automatable": "NOT_DEFINED",
                        "Recovery": "NOT_DEFINED",
                        "Safety": "NOT_DEFINED",
                        "attackComplexity": "LOW",
                        "attackRequirements": "NONE",
                        "attackVector": "NETWORK",
                        "baseScore": 9.3,
                        "baseSeverity": "CRITICAL",
                        "exploitMaturity": "NOT_DEFINED",
                        "privilegesRequired": "NONE",
                        "providerUrgency": "NOT_DEFINED",
                        "subAvailabilityImpact": "NONE",
                        "subConfidentialityImpact": "NONE",
                        "subIntegrityImpact": "NONE",
                        "userInteraction": "NONE",
                        "valueDensity": "NOT_DEFINED",
                        "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
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            "references": [
                {
                    "url": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-pjqx-v446-x7fc",
                    "name": "GitHub Security Advisory (GHSA-pjqx-v446-x7fc)",
                    "tags": [
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                },
                {
                    "url": "https://github.com/FreeRDP/FreeRDP/commit/1f7a716d39b5605bb8a83b0c3c97a6ce386609ef",
                    "name": "Patch Commit",
                    "tags": [
                        "patch"
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                },
                {
                    "name": "VulnCheck Advisory: FreeRDP before 3.28.0 Heap Buffer Overflow via crypto_rsa_common",
                    "tags": [
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                    ],
                    "url": "https://www.vulncheck.com/advisories/freerdp-before-heap-buffer-overflow-via-crypto-rsa-common"
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                    "lang": "en",
                    "value": "DavidKorczynski",
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        "adp": [
            {
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-07-20T19:27:21.868045Z",
                                "id": "CVE-2026-64620",
                                "options": [
                                    {
                                        "Exploitation": "none"
                                    },
                                    {
                                        "Automatable": "yes"
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                                        "Technical Impact": "total"
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                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
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                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
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                    "dateUpdated": "2026-07-20T19:31:27.240Z"
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