Vulnerability Report

CVE-2023-27535

Title: Authentication Bypass in libcurl FTP connection reuse

Authentication Bypass

Proof Of Concept

No public PoC currently indexed for CVE-2023-27535.

CWE Category CWE-287
Published Date Mar 30, 2023
Modified Date Jun 09, 2025
Exploit Status Not Found
Score 5.9 CVSS v3.1
Exploit Probability (EPSS)
1.61%

Vulnerability Summary

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.

Impacted Vendors

L
libcurl 1
N
netapp 6
S
splunk 1
S
sercomm 1
H
haxx 1

Reference Links

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/
CVSS v3.1
Source Entity [email protected]
Severity MEDIUM
5.9
Attack Vector
NETWORK
Complexity
HIGH
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS v3.1
Source Entity 134c704f-9b21-4f2e-91b3-4a467353bcc0
Severity MEDIUM
5.9
Attack Vector
NETWORK
Complexity
HIGH
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2023-27535 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data or affected products updated.

PUBLISHED

Vulnerability first announced in NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity HIGH
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected Stack

No specific products linked.