What is CVE-2023-5748?

CVE-2023-5748 is a low-severity vulnerability in Synology SSL Vpn Client, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 3.3/10. Published 2023-11-07.

How severe is CVE-2023-5748?

Low severity. CVSS v3 base score is 3.3 out of 10.

Buffer overflow in Synology SSL Vpn Client

CVE-2023-5748

Buffer copy without checking size of input ('Classic Buffer Overflow') vulnerability in cgi component in Synology SSL VPN Client before 1.4.7-0687 allows local users to conduct denial-of-service attacks via unspecified vectors.

Vulnerability class: Buffer Overflow

Published 2023-11-07 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 3.3 (Low). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L.

EPSS exploit prediction

EPSS: 0.002 (8.1th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 8th percentile — 8.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-120 — Buffer Copy without Checking Size of Input (Classic Buffer Overflow)

References

www.synology.com/en-global/security/advisory/Synology_SA_23_12 (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2023-5748?: CVE-2023-5748 is a low-severity vulnerability in Synology SSL Vpn Client, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 3.3/10. Published 2023-11-07.
How severe is CVE-2023-5748?: Low severity. CVSS v3 base score is 3.3 out of 10.