{
    "document": {
        "category": "csaf_base",
        "csaf_version": "2.0",
        "distribution": {
            "tlp": {
                "label": "WHITE"
            }
        },
        "lang": "en",
        "notes": [
            {
                "category": "legal_disclaimer",
                "text": "The Netherlands Cyber Security Center (henceforth: NCSC-NL) maintains this portal to enhance access to its information and vulnerabilities. The use of this information is subject to the following terms and conditions:\n\nThe vulnerabilities disclosed in this portal are gathered by NCSC-NL from a variety of open sources, which the user can retrieve from other platforms. NCSC-NL makes every reasonable effort to ensure that the content of this portal is kept up to date, and that it is accurate and complete. Nevertheless, NCSC-NL cannot entirely rule out the possibility of errors, and therefore cannot give any warranty in respect of its completeness, accuracy or real-time keeping up-to-date. NCSC-NL does not control nor guarantee the accuracy, relevance, timeliness or completeness of information obtained from these external sources. The vulnerabilities disclosed in this portal are intended solely for the convenience of professional parties to take appropriate measures to manage the risks posed to the cybersecurity. No rights can be derived from the information provided therein.\n\nNCSC-NL and the Kingdom of the Netherlands assume no legal liability or responsibility for any damage resulting from either the use or inability of use of the vulnerabilities disclosed in this portal. This includes damage resulting from the inaccuracy of incompleteness of the information contained in it.\nThe information on this page is subject to Dutch law. All disputes related to or arising from the use of this portal regarding the disclosure of vulnerabilities will be submitted to the competent court in The Hague. This choice of means also applies to the court in summary proceedings."
            }
        ],
        "publisher": {
            "category": "coordinator",
            "contact_details": "cert@ncsc.nl",
            "name": "National Cyber Security Centre",
            "namespace": "https://www.ncsc.nl/"
        },
        "title": "CVE-2026-33242",
        "tracking": {
            "current_release_date": "2026-03-29T16:14:27.486795Z",
            "generator": {
                "date": "2026-02-17T15:00:00Z",
                "engine": {
                    "name": "V.E.L.M.A",
                    "version": "1.7"
                }
            },
            "id": "CVE-2026-33242",
            "initial_release_date": "2026-03-19T15:31:28.396921Z",
            "revision_history": [
                {
                    "date": "2026-03-19T15:31:28.396921Z",
                    "number": "1",
                    "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (3).| CWES updated (1)."
                },
                {
                    "date": "2026-03-19T15:31:31.920199Z",
                    "number": "2",
                    "summary": "NCSC Score created."
                },
                {
                    "date": "2026-03-24T20:42:16.470484Z",
                    "number": "3",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (3).| CWES updated (1)."
                },
                {
                    "date": "2026-03-24T20:42:19.398516Z",
                    "number": "4",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-24T20:44:55.647732Z",
                    "number": "5",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products created (1).| References created (3).| CWES updated (1)."
                },
                {
                    "date": "2026-03-24T20:44:59.049161Z",
                    "number": "6",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-24T20:50:58.811145Z",
                    "number": "7",
                    "summary": "Unknown change."
                },
                {
                    "date": "2026-03-24T20:53:44.484889Z",
                    "number": "8",
                    "summary": "Products created (1).| Product Identifiers created (1).| Exploits created (1)."
                },
                {
                    "date": "2026-03-24T20:53:47.705389Z",
                    "number": "9",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-24T21:37:46.257052Z",
                    "number": "10",
                    "summary": "Source connected.| CVE status created. (valid)| EPSS created."
                },
                {
                    "date": "2026-03-24T21:37:47.637049Z",
                    "number": "11",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-25T21:50:35.172296Z",
                    "number": "12",
                    "summary": "References created (2)."
                },
                {
                    "date": "2026-03-25T21:50:43.426358Z",
                    "number": "13",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-29T03:16:19.251871Z",
                    "number": "14",
                    "summary": "References removed (2)."
                },
                {
                    "date": "2026-03-29T03:16:21.851701Z",
                    "number": "15",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-29T16:14:25.846889Z",
                    "number": "16",
                    "summary": "References created (2)."
                }
            ],
            "status": "interim",
            "version": "16"
        }
    },
    "product_tree": {
        "branches": [
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/>=0.39.0|<0.89.3",
                                "product": {
                                    "name": "vers:unknown/>=0.39.0|<0.89.3",
                                    "product_id": "CSAFPID-5902785",
                                    "product_identification_helper": {
                                        "cpe": "cpe:2.3:a:salvo:salvo:*:*:*:*:*:rust:*:*"
                                    }
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "salvo"
                    }
                ],
                "category": "vendor",
                "name": "salvo"
            },
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/>=0.39.0|<0.89.3",
                                "product": {
                                    "name": "vers:unknown/>=0.39.0|<0.89.3",
                                    "product_id": "CSAFPID-5902046"
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "salvo"
                    }
                ],
                "category": "vendor",
                "name": "salvo-rs"
            }
        ]
    },
    "vulnerabilities": [
        {
            "cve": "CVE-2026-33242",
            "cwe": {
                "id": "CWE-22",
                "name": "Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')"
            },
            "notes": [
                {
                    "category": "description",
                    "text": "### Details\n\nA Path Traversal and Access Control Bypass vulnerability was discovered in the salvo-proxy component of the Salvo Rust framework (v0.89.2). The vulnerability allows an unauthenticated external attacker to bypass proxy routing constraints and access unintended backend paths (e.g., protected endpoints or administrative dashboards). This issue stems from the encode_url_path function, which fails to normalize \"../\" sequences and inadvertently forwards them verbatim to the upstream server by not re-encoding the \".\" character.\n\n---\n\n### Technical Details\n\nIf someone tries to attack by sending a special code like `%2e%2e`, Salvo changes it back to `../` when it first checks the path. The proxy then gets this plain `../` value. When making the new URL to send forward, the `encode_url_path` function tries to change the path again, but its normal settings do not include the `.` (dot) character. Because of this, the proxy puts `../` straight into the new URL and sends a request like `GET /api/../admin HTTP/1.1` to the backend server.\n\n```rust\n// crates/proxy/src/lib.rs (Lines 100-105)\n\npub(crate) fn encode_url_path(path: &str) -> String {\n    path.split('/')\n        .map(|s| utf8_percent_encode(s, PATH_ENCODE_SET).to_string())\n        .collect::<Vec<_>>()\n        .join(\"/\")\n}\n```\n\n---\n\n### PoC\n\n1 - Setup an Nginx Backend Server for example\n2 - Start Salvo Proxy Gateway in other port routing to /api/\n3 - Run the curl to test the bypass:\n\n```bash\ncurl -s http://127.0.0.1:8080/gateway/api/%2e%2e%2fadmin/index.html\n```\n\n---\n\n### Impact\n\nIf attackers take advantage of this problem, they can get past API Gateway security checks and route limits without logging in. This could accidentally make internal services, admin pages, or folders visible.\n\nThe attack works because the special path is sent as-is to the backend, which often happens in systems that follow standard web address rules. Attackers might also use different ways of writing URLs or add extra parts to the web address to get past simple security checks that only look for exact `../` patterns.\n\n---\n\n### Remediation\n\nInstead of changing the text of the path manually, the proxy should use a standard way to clean up the path according to RFC 3986 before adding it to the main URL. It is better to use a trusted tool like the URL crate to join paths, or to block any path parts with “..” after decoding them. But a custom implementation maybe looks like:\n\n```rust\npub(crate) fn encode_url_path(path: &str) -> String {\n    let normalized = normalize_path(path);\n    normalized.split('/')\n        .map(|s| utf8_percent_encode(s, PATH_ENCODE_SET).to_string())\n        .collect::<Vec<_>>()\n        .join(\"/\")\n}\n\nfn normalize_path(path: &str) -> String {\n    let mut stack = Vec::new();\n    for part in path.split('/') {\n        match part {\n            \"\" | \".\" => (), \n            \"..\" => { let _ = stack.pop(); },\n            _ => stack.push(part),\n        }\n    }\n    stack.join(\"/\")\n}\n```\n---\n\n**Vulnerable code introduced in:**\nhttps://github.com/salvo-rs/salvo/commit/7bac30e6960355c58e358e402072d4a3e5c4e1bb#diff-e319bf7afcb577f7e9f4fb767005072f6335d23f306dd52e8c94f3d222610d02R20\n\n---\n\n**Author**: Tomas Illuminati",
                    "title": "github - https://api.github.com/advisories/GHSA-f842-phm9-p4v4"
                },
                {
                    "category": "description",
                    "text": "Salvo is a Rust web framework. Versions 0.39.0 through 0.89.2 have a Path Traversal and Access Control Bypass vulnerability in the salvo-proxy component. The vulnerability allows an unauthenticated external attacker to bypass proxy routing constraints and access unintended backend paths (e.g., protected endpoints or administrative dashboards). This issue stems from the encode_url_path function, which fails to normalize \"../\" sequences and inadvertently forwards them verbatim to the upstream server by not re-encoding the \".\" character. Version 0.89.3 contains a patch.",
                    "title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-33242"
                },
                {
                    "category": "description",
                    "text": "Salvo is a Rust web framework. Versions 0.39.0 through 0.89.2 have a Path Traversal and Access Control Bypass vulnerability in the salvo-proxy component. The vulnerability allows an unauthenticated external attacker to bypass proxy routing constraints and access unintended backend paths (e.g., protected endpoints or administrative dashboards). This issue stems from the encode_url_path function, which fails to normalize \"../\" sequences and inadvertently forwards them verbatim to the upstream server by not re-encoding the \".\" character. Version 0.89.3 contains a patch.",
                    "title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/33xxx/CVE-2026-33242.json"
                },
                {
                    "category": "other",
                    "text": "0.00019",
                    "title": "EPSS"
                },
                {
                    "category": "other",
                    "text": "3.4",
                    "title": "NCSC Score"
                },
                {
                    "category": "other",
                    "text": "Exploit code publicly available, There is exploit data available from source Nvd, The value of the most recent EPSS score",
                    "title": "NCSC Score top decreasing factors"
                }
            ],
            "product_status": {
                "known_affected": [
                    "CSAFPID-5902046",
                    "CSAFPID-5902785"
                ]
            },
            "references": [
                {
                    "category": "external",
                    "summary": "Source - github",
                    "url": "https://api.github.com/advisories/GHSA-f842-phm9-p4v4"
                },
                {
                    "category": "external",
                    "summary": "Source - nvd",
                    "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-33242"
                },
                {
                    "category": "external",
                    "summary": "Source - cveprojectv5",
                    "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/33xxx/CVE-2026-33242.json"
                },
                {
                    "category": "external",
                    "summary": "Source - first",
                    "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; github; nvd",
                    "url": "https://github.com/salvo-rs/salvo/security/advisories/GHSA-f842-phm9-p4v4"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; github; nvd",
                    "url": "https://github.com/salvo-rs/salvo/commit/7bac30e6960355c58e358e402072d4a3e5c4e1bb#diff-e319bf7afcb577f7e9f4fb767005072f6335d23f306dd52e8c94f3d222610d02R20"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://github.com/advisories/GHSA-f842-phm9-p4v4"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; github; nvd",
                    "url": "https://github.com/salvo-rs/salvo/releases/tag/v0.89.3"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33242"
                }
            ],
            "scores": [
                {
                    "cvss_v3": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
                        "baseScore": 7.5,
                        "baseSeverity": "HIGH"
                    },
                    "products": [
                        "CSAFPID-5902046",
                        "CSAFPID-5902785"
                    ]
                }
            ],
            "title": "CVE-2026-33242"
        }
    ]
}