CVE-2025-15079
Description
A flaw was found in curl. When performing SSH-based transfers using SCP or SFTP, libcurl could mistakenly connect to hosts not listed in the user-specified knownhosts file. This occurs if the host is present in the libssh global knownhosts file, effectively bypassing the intended host verification. This could allow a remote attacker to connect to an untrusted host, potentially leading to information disclosure or man-in-the-middle attacks.
Statement
This vulnerability is rated Important for Red Hat because libcurl, when configured for SSH-based transfers (SCP/SFTP) with a user-specified knownhosts file, may bypass this configuration and accept connections to hosts present in the system-wide libssh global knownhosts file. This could lead to unintended host trust in specific deployment scenarios.
Mitigation
To mitigate this issue, ensure that the system-wide `libssh` global knownhosts file (`/etc/ssh/ssh_known_hosts`) does not contain entries for untrusted hosts. Alternatively, avoid using `libcurl` for SCP or SFTP transfers in environments where strict enforcement of a user-specified knownhosts file is critical and the system-wide knownhosts file cannot be fully controlled. Services relying on `libssh` for host key verification may need to be restarted to apply the changes.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.1 | N/A | 5.3 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | High |
| Privileges Required | Low | N/A | None |
| User Interaction | None | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | None |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N
Understanding the Weakness (CWE)
Access Control
Technical Impact: Bypass Protection Mechanism
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
