CVE-2015-8960

moderate-risk
Published 2016-09-21

The TLS protocol 1.2 and earlier supports the rsa_fixed_dh, dss_fixed_dh, rsa_fixed_ecdh, and ecdsa_fixed_ecdh values for ClientCertificateType but does not directly document the ability to compute the master secret in certain situations with a client secret key and server public key but not a server secret key, which makes it easier for man-in-the-middle attackers to spoof TLS servers by leveraging knowledge of the secret key for an arbitrary installed client X.509 certificate, aka the "Key Compromise Impersonation (KCI)" issue.

Do I need to act?

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0.33% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
8
CVSS 8.1/10 High
NETWORK / HIGH complexity

Affected Products (15)

Transport Layer Security
System Setup

Affected Vendors

Ietf Netapp

References (12)

Press/Media Coverage http://twitter.com/matthew_d_green/statuses/630908726950674433
Mailing List http://www.openwall.com/lists/oss-security/2016/09/20/4
Broken Link http://www.securityfocus.com/bid/93071
Exploit https://kcitls.org
Third Party Advisory https://security.netapp.com/advisory/ntap-20180626-0002/
Exploit https://www.usenix.org/system/files/conference/woot15/woot15-paper-hlauschek.pdf
Press/Media Coverage http://twitter.com/matthew_d_green/statuses/630908726950674433
Mailing List http://www.openwall.com/lists/oss-security/2016/09/20/4
Broken Link http://www.securityfocus.com/bid/93071
Exploit https://kcitls.org
Third Party Advisory https://security.netapp.com/advisory/ntap-20180626-0002/
Exploit https://www.usenix.org/system/files/conference/woot15/woot15-paper-hlauschek.pdf
43
/ 100
moderate-risk
Severity 24/34 · High
Exploitability 1/34 · Minimal
Exposure 18/34 · Moderate