CVE-2015-5477
Description
A flaw was found in the way BIND handled requests for TKEY DNS resource records. A remote attacker could use this flaw to make named (functioning as an authoritative DNS server or a DNS resolver) exit unexpectedly with an assertion failure via a specially crafted DNS request packet.
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 | 7.8 | N/A |
| Attack Vector | Network | Network | N/A |
| Access Complexity | Low | Low | N/A |
| Authentication | None | None | N/A |
| Confidentiality Impact | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | Partial | Complete | N/A |
Vector
Red Hat: AV:N/AC:L/Au:N/C:N/I:N/A:P
NVD: AV:N/AC:L/Au:N/C:N/I:N/A:C
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. Upstream acknowledges Jonathan Foote as the original reporter.
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