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Case File

CVE-2021-43523

CRITICAL · CVSS 9.6 EPSS 3.26% Public Exploit

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2021-11-10 · Last synced 2026-08-04

CyberRota Analysis

This is a critical severity vulnerability with a CVSS score of 9.6. Public exploit code or proof-of-concept references have been detected in its references. It may be remotely exploitable.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Detected Signals
remote code execution code execution
GitHub PoC Links

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2021-43523
Severity
CRITICAL
CVSS
9.6
EPSS
3.26%

Original NVD Description

In uClibc and uClibc-ng before 1.0.39, incorrect handling of special characters in domain names returned by DNS servers via gethostbyname, getaddrinfo, gethostbyaddr, and getnameinfo can lead to output of wrong hostnames (leading to domain hijacking) or injection into applications (leading to remote code execution, XSS, applications crashes, etc.). In other words, a validation step, which is expected in any stub resolver, does not occur.

Related CVEs

Other vulnerabilities affecting the same vendor(s)