CVE-2021-43523
CVSS v3
9.6
CRITICAL
EPSS Score
2.9 %
exploit probability
CISA KEV
No
known exploited
Exploitation
—
SSVC status
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.
Technical details
- Published
- 2021-11-10
Frequently asked questions
What is CVE-2021-43523?
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.
Is CVE-2021-43523 actively exploited?
Active exploitation of CVE-2021-43523 has not been confirmed. The EPSS score is 2.9%, indicating the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2021-43523?
CVE-2021-43523 has a CVSS v3 base score of 9.6 (CRITICAL severity).
Is CVE-2021-43523 affecting your environment?
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