Improper restriction of communication channel to intended endpoints vulnerability in HTTP daemon in Synology SSL VPN Client before 1.2.4-02…

published 2018-07-06 8 y ago modified 2026-06-17 4 mo ago also EUVD-2018-20537

cvss: 7.3; version 3.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.8%; EPSS 0.8% chance of exploitation in 30 days, percentile 55%
public exploits: 0; none known

Improper restriction of communication channel to intended endpoints vulnerability in HTTP daemon in Synology SSL VPN Client before 1.2.4-0224 allows remote attackers to conduct man-in-the-middle attacks via a crafted payload.

Patch / fix

fixed in 1

Synology SSL VPN Client 1.2.4-0224

Exploit prediction

0.75% chance of exploitation in the next 30 days, higher than 55% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.0	7.3	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
NVD	3.0	8.1	CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	6.8	AV:N/AC:M/Au:N/C:P/I:P/A:P

Affected products

Synology SSL VPN Client

Classification

Weakness

CWE-319 Cleartext Transmission of Sensitive Information
CWE-417 Communication Channel Errors

References

synology.com /en-global/support/security/Synology_SA_18_19
vendor-advisory

Sources

CVE List CVE-2018-8929
NVD CVE-2018-8929

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary