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.
NVD Severity
Other trackers
Mailing lists
GitHub (code, issues), Aports (code, issues)


Type URI
Technical Description
Press/Media Coverage
Mailing List
Technical Description

Match rules

CPE URI Source package Min version Max version
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* firefox == None == None
cpe:2.3:a:microsoft:internet_explorer:*:*:*:*:*:*:*:* internet_explorer == None == None
cpe:2.3:a:opera:opera:*:*:*:*:*:*:*:* opera == None == None
cpe:2.3:a:apple:safari:*:*:*:*:*:*:*:* safari == None == None
cpe:2.3:a:google:chrome:*:*:*:*:*:*:*:* chrome == None == None

Vulnerable and fixed packages

Source package Branch Version Maintainer Status
firefox 3.14-community 89.0.1-r0 Rasmus Thomsen <> possibly vulnerable
firefox 3.15-community 94.0-r0 Rasmus Thomsen <> possibly vulnerable
firefox 3.16-community 101.0.1-r0 Rasmus Thomsen <> possibly vulnerable
firefox 3.17-community 109.0.1-r0 psykose <> possibly vulnerable
firefox 3.18-community 119.0-r0 Patrycja Rosa <> possibly vulnerable
firefox 3.19-community 125.0.3-r0 Patrycja Rosa <> possibly vulnerable
firefox 3.20-community 126.0.1-r0 Patrycja Rosa <> possibly vulnerable
firefox edge-community 128.0-r0 Patrycja Rosa <> possibly vulnerable