Not a U.S. government website. NDD is an independent vulnerability database by Volerion and is not affiliated with or endorsed by NIST or NVD.

CVE-2021-43523 Details

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.

Metrics

CVSS 3.x Severity and Vector Strings:

NIST: [email protected]CVSS-B:9.6 CRITICALVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

CNA: CISA-ADPCVSS-B:9.6 CRITICALVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

References to Advisories, Solutions, and Tools

By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.

URL	Source(s)	Tag(s)
https://github.com/wbx-github/uclibc-ng/commit/0f822af0445e5348ce7b7bd8ce1204244f31d174	CVE	PatchThird Party Advisory
https://uclibc-ng.org/	CVE	Vendor Advisory
https://www.openwall.com/lists/oss-security/2021/11/09/1	CVE	ExploitMailing ListThird Party Advisory
https://github.com/wbx-github/uclibc-ng/commit/0f822af0445e5348ce7b7bd8ce1204244f31d174	[email protected]	PatchThird Party Advisory
https://uclibc-ng.org/	[email protected]	Vendor Advisory
https://www.openwall.com/lists/oss-security/2021/11/09/1	[email protected]	ExploitMailing ListThird Party Advisory

see all 6 references

Weakness Enumeration

CWE-ID	CWE Name	Source
CWE-79	Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')	[email protected]
CWE-79	Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')	CISA-ADP

Affected Products

Product	Versions
uclibc uclibc	<= 0.9.33.2
CPE cpe:2.3:a:uclibc:uclibc:::::::: Remediation No remediation found in references.
uclibc-ng project uclibc-ng	< 1.0.39
CPE cpe:2.3:a:uclibc-ng_project:uclibc-ng:::::::: Remediation No remediation found in references.

Change History

6 change records found show changes

Date	Action	Recorded By
Jun 17, 2026	CVE Modified	[email protected]
Jun 17, 2026	CVE Modified	CISA-ADP
May 5, 2025	CVE Modified	CISA-ADP
Nov 21, 2024	CVE Modified	CVE
May 14, 2024	CVE Modified	[email protected]
Nov 15, 2021	Initial Analysis	[email protected]