CVE-2017-6094
The algorithm used to compute the "chk" was disclosed by reverse engineering the CPE's firmware.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.19%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.0
- 9.8 CRITICALCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 1.19% probability · 66th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-200
- Affected
- genexis/gaps
- Source
- cve@mitre.org
References
- http://seclists.org/fulldisclosure/2017/Dec/62Exploit, Mailing List, Mitigation, Third Party Advisory
- http://seclists.org/fulldisclosure/2017/Dec/62Exploit, Mailing List, Mitigation, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.