Auth bypass in Haxx Libcurl
CVE-2023-27535
An authentication bypass vulnerability exists in libcurl <8.0.0 in the FTP connection reuse feature that can result in wrong credentials being used during subsequent transfers. Previously created connections are kept in a connection pool for reuse if they match the current setup. However, certain FTP settings such as CURLOPT_FTP_ACCOUNT, CURLOPT_FTP_ALTERNATIVE_TO_USER, CURLOPT_FTP_SSL_CCC, and CURLOPT_USE_SSL were not included in the configuration match checks, causing them to match too easily. This could lead to libcurl using the wrong credentials when performing a transfer, potentially allowing unauthorized access to sensitive information.
EPSS: 0.016 (74.2th percentile) — read the EPSS interpretation.
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.
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- support@hackerone.com (Exploit, Third Party Advisory)
- support@hackerone.com (vendor-advisory, Mailing List, Third Party Advisory)
- support@hackerone.com (Third Party Advisory)
- support@hackerone.com (mailing-list, Mailing List, Third Party Advisory)
- support@hackerone.com (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2023-27535?
- CVE-2023-27535 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-2023-27535?
- Medium severity. CVSS v3 base score is 5.9 out of 10.
- Is CVE-2023-27535 known to be exploited?
- 4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.