THREATPORT/VULNERABILITY/CVE-2021-43523
CRITICAL SEVERITY

CVE-2021-43523

Uclibc vulnerability

CVSS
9.6
EPSS
3.3%
EPSS pct
87th
Exploited
No known
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.
Affected vendor
Uclibc
Affected product
Uclibc
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
Weakness type (CWE)
  • CWE-79 — Cross-Site Scripting (XSS)
Published
2021-11-10

Risk analysis

Based on its CVSS vector, this vulnerability is exploitable over the network, low attack complexity, requiring no privileges, user interaction. Successful exploitation leads to high impact to confidentiality, high impact to integrity, high impact to availability.

Its EPSS score of 3.3% reflects a lower probability of exploitation activity in the wild over the next 30 days, placing it above 87% of all scored CVEs.

Check your external exposure to CVE-2021-43523

  • Confirm whether Uclibc Uclibc is running on any internet-facing host or subdomain.
  • Match discovered service fingerprints against the version affected by CVE-2021-43523.
  • Prioritise remediation if the asset is public, business-critical, or near authentication/payment flows.

How ThreatPort helps with CVE-2021-43523

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