CPEs used by subscribers on the access network receive their individual configuration settings from a central GAPS instance.

published 2017-12-20 8 y ago modified 2026-06-17 4 mo ago also EUVD-2017-15160

cvss: 9.8; version 3.0, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.2%; EPSS 1.2% chance of exploitation in 30 days, percentile 68%
public exploits: 0; none known

CPEs used by subscribers on the access network receive their individual configuration settings from a central GAPS instance. A CPE identifies itself by the MAC address of its WAN interface and a certain "chk" value (48bit) derived from the MAC. The algorithm used to compute the "chk" was disclosed by reverse engineering the CPE's firmware. As a result, it is possible to forge valid "chk" values for any given MAC address and therefore receive the configuration settings of other subscribers' CPEs. The configuration settings often contain sensitive values, for example credentials (username/password) for VoIP services. This issue affects Genexis B.V. GAPS up to 7.2.

Patch / fix

fixed in 1

genexis gaps 7.2

Exploit prediction

1.19% chance of exploitation in the next 30 days, higher than 68% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

seclists.org http://seclists.org/fulldisclosure/2017/Dec/62 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.0	9.8	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	5.0	AV:N/AC:L/Au:N/C:P/I:N/A:N

Classification

Weakness

CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

References

seclists.org /fulldisclosure/2017/Dec/62
mailing-list, exploit, mitigation, third-party-advisory

Sources

CVE List CVE-2017-6094
NVD CVE-2017-6094

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