NTP before 4.2.8p6 and 4.3.x before 4.3.90, when configured in broadcast mode, allows man-in-the-middle attackers to conduct replay attacks by sniffing the network.
The MITRE CVE dictionary describes this issue as:
Find out more about CVE-2015-7973 from the MITRE CVE dictionary dictionary and NIST NVD.
This issue affects the versions of ntp as shipped with Red Hat Enterprise Linux 5, 6, and 7. Red Hat Product Security has rated this issue as having Moderate security impact. A future update may address this issue in Red Hat Enterprise Linux 6 and 7. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.
NOTE: The following CVSS v2 metrics and score provided are preliminary and subject to review.
| Base Score | 4.3 |
|---|---|
| Base Metrics | AV:A/AC:M/Au:N/C:N/I:P/A:P |
| Access Vector | Adjacent Network |
| Access Complexity | Medium |
| Authentication | None |
| Confidentiality Impact | None |
| Integrity Impact | Partial |
| Availability Impact | Partial |
Find out more about Red Hat support for the Common Vulnerability Scoring System (CVSS).
| Platform | Package | State |
|---|---|---|
| Red Hat Enterprise Linux 7 | ntp | Will not fix |
| Red Hat Enterprise Linux 6 | ntp | Will not fix |
| Red Hat Enterprise Linux 5 | ntp | Will not fix |
Do not use NTP's broadcast mode by not configuring the "broadcast" directive in the ntp.conf file.
Vulmon