{"id":"GHSA-rm8v-mxj3-5rmq","aliases":["GO-2023-1859"],"url":"https://o3.security/vulnerability/GHSA-rm8v-mxj3-5rmq","summary":"github.com/lestrrat-go/jwx vulnerable to Potential Padding Oracle Attack","details":"### Summary\n\nDecrypting AES-CBC encrypted JWE has Potential Padding Oracle Attack Vulnerability.\n\n### Details\n\nOn [v2.0.10](https://github.com/lestrrat-go/jwx/releases/tag/v2.0.10), decrypting AES-CBC encrypted JWE may return an error \"failed to generate plaintext from decrypted blocks: invalid padding\":\n\nhttps://github.com/lestrrat-go/jwx/blob/8840ffd4afc5839f591ff0e9ba9034af52b1643e/jwe/internal/aescbc/aescbc.go#L210-L213\n\nReporting padding error causes [Padding Oracle Attack](https://en.wikipedia.org/wiki/Padding_oracle_attack) Vulnerability.\nRFC 7516 JSON Web Encryption (JWE) says that we **MUST NOT** do this.\n\n> 11.5.  Timing Attacks\n> To mitigate the attacks described in RFC 3218 [RFC3218], the\n> recipient MUST NOT distinguish between format, padding, and length\n> errors of encrypted keys.  It is strongly recommended, in the event\n> of receiving an improperly formatted key, that the recipient\n> substitute a randomly generated CEK and proceed to the next step, to\n> mitigate timing attacks.\n\nIn addition, the time to remove padding depends on the length of the padding.\nIt may leak the length of the padding by Timing Attacks.\n\nhttps://github.com/lestrrat-go/jwx/blob/796b2a9101cf7e7cb66455e4d97f3c158ee10904/jwe/internal/aescbc/aescbc.go#L33-L66\n\nTo mitigate Timing Attacks, it MUST be done in constant time.\n\n### Impact\n\nThe authentication tag is verified, so it is not an immediate attack.\n","published":"2023-06-14T17:24:36Z","modified":"2023-11-08T04:22:49.387484Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/lestrrat-go/jwx/v2","fixedVersion":"2.0.11"},{"ecosystem":"Go","name":"github.com/lestrrat-go/jwx","fixedVersion":"1.2.26"}],"fix":{"url":"https://github.com/lestrrat-go/jwx/commit/6c41e3822485fc7e11dd70b4b0524b075d66b103","label":"lestrrat-go/jwx@6c41e38"},"references":[{"type":"WEB","url":"https://github.com/lestrrat-go/jwx/security/advisories/GHSA-rm8v-mxj3-5rmq"},{"type":"WEB","url":"https://github.com/lestrrat-go/jwx/commit/6c41e3822485fc7e11dd70b4b0524b075d66b103"},{"type":"WEB","url":"https://github.com/lestrrat-go/jwx/commit/d9ddbc8e5009cfdd8c28413390b67afa7f576dd6"},{"type":"PACKAGE","url":"https://github.com/lestrrat-go/jwx"},{"type":"WEB","url":"https://github.com/lestrrat-go/jwx/blob/796b2a9101cf7e7cb66455e4d97f3c158ee10904/jwe/internal/aescbc/aescbc.go#L33-L66"},{"type":"WEB","url":"https://github.com/lestrrat-go/jwx/blob/8840ffd4afc5839f591ff0e9ba9034af52b1643e/jwe/internal/aescbc/aescbc.go#L210-L213"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2023-11-08T04:22:49.387484Z"}}