What is the CVSS score of CVE-2021-43523?

CVE-2021-43523 has a CVSS 3.1 base score of 9.6 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H. EPSS exploitation probability: 3.3%.

Is there a public PoC exploit available for CVE-2021-43523?

Yes, a public proof-of-concept exploit is available for CVE-2021-43523. Prioritise patching immediately. EPSS: 3.3%.

Is there a patch available for CVE-2021-43523?

Yes, a patch is available for CVE-2021-43523. Update the affected software to the latest version immediately.

Uclibc CVE-2021-43523

CRITICAL

Cross-site Scripting (XSS) (CWE-79)

2021-11-10 cve@mitre.org

RCE XSS Uclibc Uclibc Ng

9.6

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

9.6 CRITICAL

AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

CVE Published

Nov 10, 2021 - 15:15 nvd

CRITICAL 9.6

DescriptionNVD

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.

AnalysisAI

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. Rated critical severity (CVSS 9.6), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.

Technical ContextAI

This vulnerability is classified as Cross-Site Scripting (XSS) (CWE-79), which allows attackers to inject malicious scripts into web pages viewed by other users. 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 products include: Uclibc, Uclibc-Ng Project Uclibc-Ng. Version information: before 1.0.39.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Sanitize all user input, use Content-Security-Policy headers, encode output contextually (HTML, JS, URL). Use frameworks with built-in XSS protection.