It was found that when ntp is configured with rate limiting for all associations the limits are also applied to responses received from its configured sources. A remote attacker who knows the sources can cause a denial of service by preventing ntpd from accepting valid responses from its sources.
Find out more about CVE-2016-7426 from the MITRE CVE dictionary dictionary and NIST NVD.
| Base Score | 4.3 |
|---|---|
| Base Metrics | AV:N/AC:M/Au:N/C:N/I:N/A:P |
| Access Vector | Network |
| Access Complexity | Medium |
| Authentication | None |
| Confidentiality Impact | None |
| Integrity Impact | None |
| Availability Impact | Partial |
| CVSS3 Base Score | 5.9 |
|---|---|
| CVSS3 Base Metrics | CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
| Attack Vector | Network |
| Attack Complexity | High |
| Privileges Required | None |
| User Interaction | None |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity Impact | None |
| Availability Impact | High |
Find out more about Red Hat support for the Common Vulnerability Scoring System (CVSS).
| Platform | Errata | Release Date |
|---|---|---|
| Red Hat Enterprise Linux 6 (ntp) | RHSA-2017:0252 | 2017-02-06 |
| Red Hat Enterprise Linux 7 (ntp) | RHSA-2017:0252 | 2017-02-06 |
| Platform | Package | State |
|---|---|---|
| Red Hat Enterprise Linux 5 | ntp | Will not fix |
If you choose to use restrict default limited ..., be sure to use restrict source ... (without limited) to avoid this attack.
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