Auth bypass in Haxx Libcurl

CVE-2016-5420

curl and libcurl before 7.50.1 do not check the client certificate when choosing the TLS connection to reuse, which might allow remote attackers to hijack the authentication of the connection by leveraging a previously created connection w…

EPSS: 0.011 (78.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2016-5420?
CVE-2016-5420 is a high-severity vulnerability in Haxx Libcurl, classified under Improper Authorization. CVSS score: 7.5/10. Published 2016-08-10.
How severe is CVE-2016-5420?
High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2016-5420 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.