NULL pointer dereference in Libssh

CVE-2023-3603

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 3.1 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L.

EPSS exploit prediction

EPSS: 0.009 (58.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 58.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2023-3603: held from 0.009 to 0.009.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2023-3603?
CVE-2023-3603 is a low-severity vulnerability in Libssh, classified under NULL Pointer Dereference. CVSS score: 3.1/10. Published 2023-07-21.
How severe is CVE-2023-3603?
Low severity. CVSS v3 base score is 3.1 out of 10.
Is CVE-2023-3603 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.