{"id":"GHSA-3f6p-5ww8-9rcr","aliases":[],"url":"https://o3.security/vulnerability/GHSA-3f6p-5ww8-9rcr","summary":"MySQL2: Auth Plugin Downgrade to mysql_clear_password Leaks Plaintext Credentials","details":"## Summary\n\nA rogue MySQL server (or MITM) can force mysql2 to send credentials in **plaintext** by requesting an auth switch to `mysql_clear_password`. The driver complies without verifying that TLS is active.\n\n## Details\n\n`mysql_clear_password` is registered as a default standard plugin in `lib/commands/auth_switch.js` (line 21). When a server sends an AuthSwitchRequest (0xFE) requesting `mysql_clear_password`, the driver executes it without checking for TLS. The plugin (`lib/auth_plugins/mysql_clear_password.js`) returns `Buffer.from(password + '\\0')`.\n\nNote: `caching_sha2_password` plugin DOES check for SSL before sending cleartext (line 77). But `mysql_clear_password` has no such guard.\n\n## Attack Scenario\n\n1. Attacker operates rogue MySQL server or performs MITM\n2. Server advertises `caching_sha2_password` in handshake\n3. Client sends hashed auth response\n4. Server replies with AuthSwitchRequest to `mysql_clear_password`\n5. Client sends password in plaintext\n6. Attacker captures plaintext password\n\n## PoC\n\nRogue MySQL server (Node.js, ~80 lines) that captures plaintext passwords from mysql2 clients. Tested against mysql2 3.20.0. Full PoC available on request.\n\n## Suggested Fix\n\nRemove `mysql_clear_password` from `standardAuthPlugins`, or add a guard requiring TLS/unix socket before allowing cleartext auth.\n\n## Impact\n\n- mysql2: 9M weekly downloads\n- Any application connecting without TLS is vulnerable to credential theft\n- Cloud environments with untrusted network paths are especially at risk","published":"2026-09-01T16:40:34Z","modified":"2026-09-01T16:45:03.787110831Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"mysql2","fixedVersion":"3.22.0"}],"fix":{"url":"https://github.com/sidorares/node-mysql2/pull/4236","label":"sidorares/node-mysql2#4236"},"references":[{"type":"WEB","url":"https://github.com/sidorares/node-mysql2/security/advisories/GHSA-3f6p-5ww8-9rcr"},{"type":"WEB","url":"https://github.com/sidorares/node-mysql2/issues/1617"},{"type":"WEB","url":"https://github.com/sidorares/node-mysql2/pull/4236"},{"type":"WEB","url":"https://github.com/sidorares/node-mysql2/commit/884bec56288d827939d0dd3f1f4ae476fbc8dbeb"},{"type":"PACKAGE","url":"https://github.com/sidorares/node-mysql2"},{"type":"WEB","url":"https://github.com/sidorares/node-mysql2/releases/tag/v3.22.0"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-01T16:45:03.787110831Z"}}