In curl and libcurl 7.52.0 to and including 7.53.1, libcurl would attempt to resume a TLS session even if the client certificate had changed. That is unacceptable since a server by specification is allowed to skip the client certificate check on resume, and may instead use the old identity which was established by the previous certificate (or no certificate). libcurl supports by default the use of TLS session id/ticket to resume previous TLS sessions to speed up subsequent TLS handshakes. They are used when for any reason an existing TLS connection couldn't be kept alive to make the next handshake faster. This flaw is a regression and identical to CVE-2016-5419 reported on August 3rd 2016, but affecting a different version range.
The MITRE CVE dictionary describes this issue as:
Find out more about CVE-2017-7468 from the MITRE CVE dictionary dictionary and NIST NVD.
NOTE: The following CVSS v3 metrics and score provided are preliminary and subject to review.
| CVSS3 Base Score | 4.8 |
|---|---|
| CVSS3 Base Metrics | CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N |
| Attack Vector | Network |
| Attack Complexity | High |
| Privileges Required | None |
| User Interaction | None |
| Scope | Unchanged |
| Confidentiality | Low |
| Integrity Impact | Low |
| Availability Impact | None |
| Platform | Package | State |
|---|---|---|
| Red Hat Software Collections for Red Hat Enterprise Linux | httpd24-curl | Not affected |
| Red Hat JBoss Web Server 3.0 | curl | Not affected |
| Red Hat Enterprise Linux 7 | curl | Not affected |
| Red Hat Enterprise Linux 6 | curl | Not affected |
| Red Hat Enterprise Linux 5 | curl | Not affected |
| RHEV Manager 3 | mingw-virt-viewer | Not affected |
| .NET Core 2.0 on Red Hat Enterprise Linux | rh-dotnet20-curl | Not affected |
| .NET Core 1.0 on Red Hat Enterprise Linux | rh-dotnetcore10-curl | Not affected |
| .NET Core 1.0 on Red Hat Enterprise Linux | rh-dotnetcore11-curl | Not affected |
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