Vulnerability Report

CVE-2023-27538

Title: Authentication Bypass in libcurl SSH connection reuse

Authentication Bypass

Proof Of Concept

No public PoC currently indexed for CVE-2023-27538.

CWE Category CWE-287
Published Date Mar 30, 2023
Modified Date Jun 09, 2025
Exploit Status Not Found
Score 5.5 CVSS v3.1
Exploit Probability (EPSS)
0.01%

Vulnerability Summary

CVE-2023-27538: An authentication bypass vulnerability exists in libcurl prior to v8.0.0 where it reuses a previously established SSH connection despite the fact that an SSH option was modified, which should have prevented reuse. libcurl maintains a pool of previously used connections to reuse them for subsequent transfers if the configurations match. However, two SSH settings were omitted from the configuration check, allowing them to match easily, potentially leading to the reuse of an inappropriate connection.

Impacted Vendors

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

Reference Links

https://hackerone.com/reports/1898475 https://lists.debian.org/debian-lts-announce/2023/04/msg00025.html https://security.gentoo.org/glsa/202310-12 https://security.netapp.com/advisory/ntap-20230420-0010/ https://hackerone.com/reports/1898475 https://lists.debian.org/debian-lts-announce/2023/04/msg00025.html https://security.gentoo.org/glsa/202310-12 https://security.netapp.com/advisory/ntap-20230420-0010/
CVSS v3.1
Source Entity [email protected]
Severity MEDIUM
5.5
Attack Vector
LOCAL
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
CVSS v3.1
Source Entity 134c704f-9b21-4f2e-91b3-4a467353bcc0
Severity HIGH
7.7
Attack Vector
LOCAL
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2023-27538 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 LOCAL
Complexity LOW
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected Stack

No specific products linked.