An information exposure vulnerability has been found in NetworkManager when dnsmasq is used in DNS processing mode. An attacker in control of a DNS server could receive DNS queries even though a Virtual Private Network (VPN) was configured on the vulnerable machine.
Find out more about CVE-2018-1000135 from the MITRE CVE dictionary dictionary and NIST NVD.
This issue did not affect the versions of NetworkManager as shipped with Red Hat Enterprise Linux 5 and 6 as they did not include support for dnsmasq DNS resolver.
NOTE: The following CVSS v3 metrics and score provided are preliminary and subject to review.
| CVSS3 Base Score | 4.8 |
|---|---|
| CVSS3 Base Metrics | CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L |
| Attack Vector | Network |
| Attack Complexity | High |
| Privileges Required | None |
| User Interaction | None |
| Scope | Unchanged |
| Confidentiality | Low |
| Integrity Impact | None |
| Availability Impact | Low |
| Platform | Package | State |
|---|---|---|
| Red Hat Enterprise Linux 7 | NetworkManager | Affected |
| Red Hat Enterprise Linux 6 | NetworkManager | Not affected |
| Red Hat Enterprise Linux 5 | NetworkManager | Not affected |
We suggest to keep the default `dns=default` in the NetworkManager configuration file to prevent DNS queries leaks to possibly hostile DNS servers.
Vulmon