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TI-2021-19416 Aliases CVE-2021-43523GHSA-65xv-vmv6-8r3f

In uClibc and uClibc-ng before 1.0.39, incorrect handling of special characters in domain…

Priority HIGH 76CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Cross-site scripting
Confidentiality · integrity · availability
High · High · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-79.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.03073 87th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:uclibc:uclibc:*:*:*:*:*:*:*:*up to 0.9.33.2VulnerableuClibC
cpe:2.3:a:uclibc-ng_project:uclibc-ng:*:*:*:*:*:*:*:*before 1.0.39VulnerableUclibc-ng Project
  • cpe:2.3:a:uclibc:uclibc:*:*:*:*:*:*:*:* Versions up to 0.9.33.2 Vulnerable ·uClibC
  • cpe:2.3:a:uclibc-ng_project:uclibc-ng:*:*:*:*:*:*:*:* Versions before 1.0.39 Vulnerable ·Uclibc-ng Project

Remediation

No fixed version listed by the sources yet.

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-43523
  2. 2026-10-03 Alias added: GHSA-65xv-vmv6-8r3f

References

Exploit 1

Patch 1

Advisory 1

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences