ProFTPD ACL Bypass via /proc/self/root Path Prefix in RNFR_CVE-2026-35025

{
    "lastseen": "",
    "description": "ProFTPD through 1.3.9b and 1.3.10rc2 contains an access control bypass vulnerability that allows authenticated FTP users to circumvent Directory ACL restrictions by prefixing paths with /proc/self/root in the RNFR command handler. Attackers can exploit the unresolved symlink components in dir_canonical_path() to cause dir_check() to perform lexical path comparisons that match no configured Directory block, enabling rename operations on files in DenyAll-protected directories and subsequent retrieval of those files. Mitigation: Sessions configured with DefaultRoot (chroot) are not affected, as chroot changes the directory to which /proc/self/root resolves.",
    "published": "2026-06-24T13:21:42.281Z",
    "modified": "2026-06-24T13:21:42.281Z",
    "type": "cve",
    "title": "ProFTPD ACL Bypass via /proc/self/root Path Prefix in RNFR",
    "source": "VulnCheck",
    "references": "https://github.com/proftpd/proftpd/issues/2170\nhttp://www.proftpd.org/\nhttps://www.vulncheck.com/advisories/proftpd-acl-bypass-via-proc-self-root-path-prefix-in-rnfr",
    "id": "CVE-2026-35025",
    "bulletinFamily": "",
    "cwe": [
        "CWE-59"
    ],
    "cvelist": null,
    "sourceData": "ProFTPD Project ProFTPD 0\nProFTPD Project ProFTPD 0",
    "sourceHref": "",
    "cvss": {
        "score": 8.6,
        "severity": "HIGH",
        "vector": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
        "version": "4.0"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "ProFTPD",
    "version": "1.3.9b, 1.3.10rc2",
    "vendor": "ProFTPD Project",
    "ai_description": "Access control bypass vulnerability allowing authenticated FTP users to circumvent Directory ACL restrictions",
    "ai_severity": "High",
    "ai_vendor": "ProFTPD Project",
    "ai_product": "ProFTPD",
    "ai_version": "1.3.9b, 1.3.10rc2",
    "ai_score": 8.6
}