CVE-2017-9109
CWE-119Published: June 18, 2020· Updated: Jun 17, 2026
Official Description
An issue was discovered in adns before 1.5.2. It fails to ignore apparent answers before the first RR that was found the first time. when this is fixed, the second answer scan finds the same RRs at the first. Otherwise, adns can be confused by interleaving answers for the CNAME target, with the CNAME itself. In that case the answer data structure (on the heap) can be overrun. With this fixed, it prefers to look only at the answer RRs which come after the CNAME, which is at least arguably correct.
Technical Analysis
CVE-2017-9109 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.
From a weakness classification perspective (CWE-119): Buffer overflow vulnerabilities can lead to arbitrary code execution or denial of service by corrupting adjacent memory.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (12)
Quick Facts
Related CVEs (CWE-119)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2017-9109 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts