{"id":"CVE-2026-57079","state":"PUBLISHED","title":"Net::BitTorrent versions before 2.1.0 for Perl write files outside the download directory via path traversal in peer-supplied metadata","description":"Net::BitTorrent versions before 2.1.0 for Perl write files outside the download directory via path traversal in peer-supplied metadata.\n\nNet::BitTorrent validates file path components only on the .torrent-file ingest path. The peer and magnet metadata path (_on_metadata_received, reached from the BEP09 ut_metadata extension) passes attacker-supplied file names straight to Storage::add_file and Storage::_parse_file_tree, where Path::Tiny's child() does not collapse \"..\". A v2 file tree key, a v1 files[].path element, or a single-file name containing \"..\" segments therefore resolves outside the download directory.\n\nBecause the peer also controls the piece hashes and the served bytes, content verification passes, so a malicious magnet or peer writes attacker-chosen content to an attacker-chosen path on the downloading host.","publishedAt":"2026-06-30T11:04:32.211Z","updatedAt":"2026-07-20T06:42:11.512Z","severity":{"score":5.3,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","source":"CISA-ADP"},"assigner":"CPANSec","products":["SANKO Net::BitTorrent"],"affected":[{"vendor":"SANKO","product":"Net::BitTorrent","packageName":"Net-BitTorrent","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"2.1.0","versionType":"custom"}],"collectionURL":"https://cpan.org/modules","programFiles":["lib/Net/BitTorrent/Torrent.pm","lib/Net/BitTorrent/Storage.pm","lib/Net/BitTorrent/Storage/File.pm"],"programRoutines":[{"name":"Net::BitTorrent::Torrent::_on_metadata_received"},{"name":"Net::BitTorrent::Storage::add_file"},{"name":"Net::BitTorrent::Storage::_parse_file_tree"}],"repo":"https://github.com/sanko/Net-BitTorrent.pm"}],"references":["https://github.com/sanko/Net-BitTorrent.pm/security/advisories/GHSA-5wc6-r65f-62rr","https://metacpan.org/release/SANKO/Net-BitTorrent-v2.1.0/changes"],"weaknesses":["CWE-22"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/57xxx/CVE-2026-57079.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-57079","state":"PUBLISHED","datePublished":"2026-06-30T11:04:32.211Z","dateUpdated":"2026-07-20T06:42:11.512Z","assignerShortName":"CPANSec","assignerOrgId":"9b29abf9-4ab0-4765-b253-1875cd9b441e","dateReserved":"2026-06-23T18:20:33.513Z"},"containers":{"cna":{"title":"Net::BitTorrent versions before 2.1.0 for Perl write files outside the download directory via path traversal in peer-supplied metadata","descriptions":[{"lang":"en","value":"Net::BitTorrent versions before 2.1.0 for Perl write files outside the download directory via path traversal in peer-supplied metadata.\n\nNet::BitTorrent validates file path components only on the .torrent-file ingest path. The peer and magnet metadata path (_on_metadata_received, reached from the BEP09 ut_metadata extension) passes attacker-supplied file names straight to Storage::add_file and Storage::_parse_file_tree, where Path::Tiny's child() does not collapse \"..\". A v2 file tree key, a v1 files[].path element, or a single-file name containing \"..\" segments therefore resolves outside the download directory.\n\nBecause the peer also controls the piece hashes and the served bytes, content verification passes, so a malicious magnet or peer writes attacker-chosen content to an attacker-chosen path on the downloading host."}],"affected":[{"vendor":"SANKO","product":"Net::BitTorrent","packageName":"Net-BitTorrent","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"2.1.0","versionType":"custom"}],"collectionURL":"https://cpan.org/modules","programFiles":["lib/Net/BitTorrent/Torrent.pm","lib/Net/BitTorrent/Storage.pm","lib/Net/BitTorrent/Storage/File.pm"],"programRoutines":[{"name":"Net::BitTorrent::Torrent::_on_metadata_received"},{"name":"Net::BitTorrent::Storage::add_file"},{"name":"Net::BitTorrent::Storage::_parse_file_tree"}],"repo":"https://github.com/sanko/Net-BitTorrent.pm"}],"references":[{"url":"https://github.com/sanko/Net-BitTorrent.pm/security/advisories/GHSA-5wc6-r65f-62rr","tags":["vendor-advisory"]},{"url":"https://metacpan.org/release/SANKO/Net-BitTorrent-v2.1.0/changes","tags":["release-notes"]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-22","description":"CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"CPANSec","orgId":"9b29abf9-4ab0-4765-b253-1875cd9b441e","dateUpdated":"2026-07-20T06:42:11.512Z"},"solutions":[{"lang":"en","value":"Upgrade to version 2.1.0 or later."}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"cpansec-cna-tool 0.1"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":5.3,"attackVector":"NETWORK","baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","integrityImpact":"NONE","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"NONE","privilegesRequired":"NONE","confidentialityImpact":"LOW"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-06-30T13:52:00.535187Z","id":"CVE-2026-57079","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-06-30T13:52:04.135Z"}}]}}}