CVE-2021-31227
CWE-787Published: August 19, 2021· Updated: Jun 17, 2026
Official Description
An issue was discovered in HCC embedded InterNiche 4.0.1. A potential heap buffer overflow exists in the code that parses the HTTP POST request, due to an incorrect signed integer comparison. This vulnerability requires the attacker to send a malformed HTTP packet with a negative Content-Length, which bypasses the size checks and results in a large heap overflow in the wbs_multidata buffer copy.
Technical Analysis
CVE-2021-31227 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 availability disruption (denial of service), with a CVSS base score of 7.5.
From a weakness classification perspective (CWE-787): Out-of-bounds write vulnerabilities can lead to data corruption, crashes, or arbitrary code execution.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (4)
Quick Facts
Related CVEs (CWE-787)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2021-31227 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts