CVE-2016-1285
Description
A denial of service flaw was found in the way BIND processed certain control channel input. A remote attacker able to send a malformed packet to the control channel could use this flaw to cause named to crash.
Mitigation
Restrict access to the control channel (by using the "controls" configuration statement in named.conf) to allow connection only from trusted systems.
Note that if no "controls" statement is present, named defaults to allowing control channel connections only from localhost (127.0.0.1 and ::1) if and only if the file rndc.key exists in the configuration directory and contains valid key syntax. If rndc.key is not present and no "controls" statement is present in named.conf, named will not accept commands on the control channel.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v2 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5 | 4.3 | N/A |
| Attack Vector | Network | Network | N/A |
| Access Complexity | Low | Medium | N/A |
| Authentication | None | None | N/A |
| Confidentiality Impact | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | Partial | Partial | N/A |
Vector
Red Hat: AV:N/AC:L/Au:N/C:N/I:N/A:P
NVD: AV:N/AC:M/Au:N/C:N/I:N/A:P
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
While assertion is good for catching logic errors and reducing the chances of reaching more serious vulnerability conditions, an attacker can still cause a denial of service if they can trigger an assert statement, and if the scope of the assert() extends beyond the attacker's own session. For example, if a server handles multiple simultaneous connections, if an assert() occurs in one single connection that causes all other connections to be dropped, this could be a significant denial of service.
Acknowledgements
Red Hat would like to thank ISC for reporting this issue.
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