Vulnerability · 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.
Published Mar 30, 2023 · catalog updated Oct 14, 2026 · An authentication bypass vulnerability
Check if you run it
No confirmed exploitation is on record for CVE-2023-27535. EPSS is 1.80%. Act only if a listed version of An authentication bypass vulnerability is installed.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (An authentication bypass vulnerability).
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- Medium5.9
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 1.80%
- Remediation
- Advisory link
- Affected products
- cpe debian/debian linux · cpe fedoraproject/fedora · cpe haxx/libcurl · cpe netapp/active iq unified manager · cpe netapp/h300s firmware · cpe netapp/h410s firmware
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.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe debian/debian linux10.0
- cpe fedoraproject/fedora36
- cpe haxx/libcurlversion unspecified
- cpe netapp/active iq unified managerversion unspecified
- cpe netapp/h300s firmwareversion unspecified
- cpe netapp/h410s firmwareversion unspecified
- cpe netapp/h500s firmwareversion unspecified
- cpe netapp/h700s firmwareversion unspecified
- cpe netapp/ontap 9version unspecified
- cpe splunk/universal forwarderversion unspecified
How to fix CVE-2023-27535
Recommended remediation
A patch or advisory reference is linked. Open the original publisher for availability by product version.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2023-27535. EPSS is 1.80%. Act only if a listed version of An authentication bypass vulnerability is installed.
Which versions are affected?
Compare what you have installed with debian/debian linux 10.0. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-287: Improper Authentication; CWE-305. EPSS 1.80%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Mar 30, 2023 · NIST NVD
Detected
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 CU
Oct 14, 2026 · NIST NVD
Updated
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 CU
Sources
- CVE.orgVulnerability recordCVE-2023-27535
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2023-27535
30-day exploitation probability 1.8%
first.org - NIST NVDVulnerability recordCVE-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.
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 16, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.