What’s Vulnerable › Vulnerabilities
CVE-2023-27535
- Severity: medium (CVSS 5.9 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 1.8% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2023-03-30 · updated 2026-10-24
- Weakness: CWE-305
Description
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.
Affected products
- Debian Linux: 10.0
- Fedoraproject Fedora: 36
- curl: from 7.13.0 through 7.88.1
- Active IQ Unified Manager for VMware vSphere, Linux, and Microsoft Windows: all versions
- NetApp H300S Firmware: all versions
- NetApp H410S Firmware: all versions
- NetApp H500S Firmware: all versions
- NetApp H700S Firmware: all versions
- NetApp Ontap 9: all versions
- Splunk Universal Forwarder: from 8.2.0 before 8.2.12; from 9.0.0 before 9.0.6; 9.1.0 — fixed in 8.2.12, 9.0.6
How to fix
Upgrade to a fixed version: Splunk Universal Forwarder 8.2.12, 9.0.6. Check the vendor advisory for mitigations.
References
- https://hackerone.com/reports/1892780
- https://lists.debian.org/debian-lts-announce/2023/04/msg00025.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/36NBD5YLJXXEDZLDGNFCERWRYJQ6LAQW/
- https://security.gentoo.org/glsa/202310-12
- https://security.netapp.com/advisory/ntap-20230420-0010/
- https://hackerone.com/reports/1892780
- https://lists.debian.org/debian-lts-announce/2023/04/msg00025.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/36NBD5YLJXXEDZLDGNFCERWRYJQ6LAQW/
- https://security.gentoo.org/glsa/202310-12
- https://security.netapp.com/advisory/ntap-20230420-0010/
- https://cert-portal.siemens.com/productcert/html/ssa-398330.html
- https://cert-portal.siemens.com/productcert/html/ssa-806742.html
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