If an application encounters a fatal protocol error and then calls SSL_shutdown() twice (once to send a close_notify, and once to receive one) then OpenSSL can respond differently to the calling application if a 0 byte record is received with invalid padding compared to if a 0 byte record is received with an invalid MAC. If the application then behaves differently based on that in a way that is detectable to the remote peer, then this amounts to a padding oracle that could be used to decrypt data. In order for this to be exploitable "non-stitched" ciphersuites must be in use. Stitched ciphersuites are optimised implementations of certain commonly used ciphersuites. Also the application must call SSL_shutdown() twice even if a protocol error has occurred (applications should not do this but some do anyway). Fixed in OpenSSL 1.0.2r (Affected 1.0.2-1.0.2q).
Metrics
Affected Vendors & Products
References
History
No history.
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Status: PUBLISHED
Assigner: openssl
Published:
Updated: 2024-09-17T04:20:35.057Z
Reserved: 2018-11-28T00:00:00
Link: CVE-2019-1559
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No data.
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Status : Modified
Published: 2019-02-27T23:29:00.277
Modified: 2024-11-21T04:36:48.960
Link: CVE-2019-1559
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