A bug was recently found in our DNS packet parsing/generation code, which, when exploited, can cause individual threads (disabling service) or whole processes (allowing a supervisor to restart them) to crash with just one or a few query packets.
- CVE: CVE-2015-5230
- Date: 2nd of September 2015
- Credit: Pyry Hakulinen and Ashish Shakla at Automattic
- Affects: PowerDNS Authoritative Server 3.4.0 through 3.4.5
- Not affected: PowerDNS Authoritative Server 3.4.6
- Severity: High
- Impact: Degraded service or Denial of service
- Exploit: This problem can be triggered by sending specially crafted query packets
- Risk of system compromise: No
- Solution: Upgrade to a non-affected version
- Workaround: Run the Authoritative Server inside a supervisor when `distributor-threads` is set to `1` to prevent Denial of Service. No workaround for the degraded service exists
PowerDNS Authoritative Server 3.4.0-3.4.5 are affected. No other versions are affected. The PowerDNS Recursor is not affected.
PowerDNS Authoritative Server 3.4.6 contains a fix to this issue. A minimal patch is available.
This issue is entirely unrelated to Security Advisory 2015-01/CVE-2015-1868.
We’d like to thank Pyry Hakulinen and Ashish Shakla at Automattic for finding and subsequently reporting this bug.