CVE-2023-3603

LOW

libssh < 0.8.9 - Denial of Service via SFTP Read Request Memory Allocation Failure

Title source: llm
STIX 2.1

Description

A missing allocation check in sftp server processing read requests may cause a NULL dereference on low-memory conditions. The malicious client can request up to 4GB SFTP reads, causing allocation of up to 4GB buffers, which was not being checked for failure. This will likely crash the authenticated user's sftp server connection (if implemented as forking as recommended). For thread-based servers, this might also cause DoS for legitimate users. Given this code is not in any released versions, no security releases have been issued.

References (2)

Core 2
Core References
Third Party Advisory vdb-entry x_refsource_redhat
https://access.redhat.com/security/cve/CVE-2023-3603
Issue Tracking, Third Party Advisory issue-tracking x_refsource_redhat
https://bugzilla.redhat.com/show_bug.cgi?id=2221791

Scores

CVSS v3 3.1
EPSS 0.0077
EPSS Percentile 50.9%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-476
Status published
Products (1)
libssh/libssh < 0.8.9
Published Jul 21, 2023
Tracked Since Feb 18, 2026