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.

Weakness

The authentication algorithm is sound, but the implemented mechanism can be bypassed as the result of a separate weakness that is primary to the authentication error.

Affected Software

Name	Vendor	Start Version	End Version
Libcurl	Haxx	7.13.0 (including)	7.88.1 (including)
Red Hat Enterprise Linux 8	RedHat	curl-0:7.61.1-30.el8_8.2	*
Red Hat Enterprise Linux 8.6 Extended Update Support	RedHat	curl-0:7.61.1-22.el8_6.12	*
Red Hat Enterprise Linux 9	RedHat	curl-0:7.76.1-23.el9_2.1	*
Red Hat Enterprise Linux 9	RedHat	curl-0:7.76.1-23.el9_2.1	*
Curl	Ubuntu	bionic	*
Curl	Ubuntu	esm-infra-legacy/trusty	*
Curl	Ubuntu	esm-infra/bionic	*
Curl	Ubuntu	esm-infra/focal	*
Curl	Ubuntu	esm-infra/xenial	*
Curl	Ubuntu	focal	*
Curl	Ubuntu	jammy	*
Curl	Ubuntu	kinetic	*
Curl	Ubuntu	lunar	*
Curl	Ubuntu	trusty	*
Curl	Ubuntu	trusty/esm	*
Curl	Ubuntu	upstream	*
Curl	Ubuntu	xenial	*

NVD	https://nvd.nist.gov/vuln/detail/CVE-2023-27535
CWE	https://cwe.mitre.org/data/definitions/305.html

Authentication Bypass by Primary Weakness

Weakness

Affected Software

References