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TI-2023-05287 Aliases CVE-2023-5748GHSA-3744-988x-mqxh

Buffer overflow in Synology SSL VPN Client

Priority LOW 24CWE-120Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-120 and the CVSS impact.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00206 10th percentileScored 2026-11-07
Fix Fixed Synology SSL VPN Client (Synology): 1.4.7-0687

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
SynologySynology SSL VPN Clientbefore 1.4.7-06871.4.7-0687Patch availableCNA
  • Synology SSL VPN Client VendorSynology Affected before 1.4.7-0687 Fixed in 1.4.7-0687 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:synology:ssl_vpn_client:*:*:*:*:*:*:*:*before 1.4.7-0687VulnerableSynology
  • cpe:2.3:a:synology:ssl_vpn_client:*:*:*:*:*:*:*:* Versions before 1.4.7-0687 Vulnerable ·Synology

Remediation

  • Fix · CNA Synology SSL VPN Client (Synology) Fixed in 1.4.7-0687

Timeline

  1. 2026-10-02 Threatist record created from CVE-2023-5748
  2. 2026-10-03 Alias added: GHSA-3744-988x-mqxh

References

Advisory 1

  • TI-2018-09531 Lack of administrator control over security vulnerability in client.cgi in Synology SSL… CVSS 3.0HIGH 8.8
  • TI-2021-22574 A plaintext storage of a password vulnerability in Synology SSL VPN Client before… CVSS 3.1HIGH 8.1
  • TI-2018-06467 Cleartext transmission of sensitive information in Synology SSL VPN Client CVSS 3.0HIGH 8.1
  • TI-2021-22573 A files or directories accessible to external parties vulnerability in Synology SSL VPN… CVSS 3.1MEDIUM 6.5

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences