CVE-2017-3733: Encrypt-Then-Mac renegotiation crash

Severity: high (CVSS 7.5 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 12.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2017-05-04 · updated 2026-06-17
Weakness: CWE-20

Description

During a renegotiation handshake if the Encrypt-Then-Mac extension is negotiated where it was not in the original handshake (or vice-versa) then this can cause OpenSSL 1.1.0 before 1.1.0e to crash (dependent on ciphersuite). Both clients and servers are affected.

Affected products

HP Operations Agent: 11.14, 11.15
OpenSSL: 1.1.0, 1.1.0a, 1.1.0b, 1.1.0c, 1.1.0d

References

http://www.oracle.com/technetwork/security-advisory/cpujan2018-3236628.html
http://www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.html
http://www.securityfocus.com/bid/96269
http://www.securitytracker.com/id/1037846
https://github.com/openssl/openssl/commit/4ad93618d26a3ea23d36ad5498ff4f59eff3a4d2
https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbgn03728en_us
https://www.openssl.org/news/secadv/20170216.txt
https://www.oracle.com/technetwork/security-advisory/cpuapr2019-5072813.html
http://www.oracle.com/technetwork/security-advisory/cpujan2018-3236628.html
http://www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.html
http://www.securityfocus.com/bid/96269
http://www.securitytracker.com/id/1037846

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