Auth bypass in Haxx Libcurl

CVE-2023-27536

An authentication bypass vulnerability exists libcurl <8.0.0 in the connection reuse feature which can reuse previously established connections with incorrect user permissions due to a failure to check for changes in the CURLOPT_GSSAPI_DELEGATION option. This vulnerability affects krb5/kerberos/negotiate/GSSAPI transfers and could potentially result in unauthorized access to sensitive information. The safest option is to not reuse connections if the CURLOPT_GSSAPI_DELEGATION option has been changed.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.016 (74.3th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 74th percentile — 74.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2023-27536: held from 0.016 to 0.016.

EPSS over last 30 days · oldest: 0.016 · newest: 0.016 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2023-27536?
CVE-2023-27536 is a medium-severity vulnerability in Haxx Libcurl, classified under Authentication Bypass by Primary Weakness. CVSS score: 5.9/10. Published 2023-03-30.
How severe is CVE-2023-27536?
Medium severity. CVSS v3 base score is 5.9 out of 10.
Is CVE-2023-27536 known to be exploited?
4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.