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CVE-2017-17562

High CVSS 8.1 Known exploited

Published 2017-12-12 · last changed 2026-06-17 · added to CISA KEV 2021-12-10

This one is being exploited in the wild.

CISA added CVE-2017-17562 to the Known Exploited Vulnerabilities catalog on 2021-12-10. Federal agencies are required to remediate it on a deadline. If you have affected machines, this is the class of finding that moves ahead of the rest of the queue.

The fix

We hold no Microsoft remediation data for CVE-2017-17562, which normally means it is not a Windows CVE. For non-Microsoft software the fix is the vendor's own updated release, and the affected versions are listed below.

What it is

Embedthis GoAhead before 3.6.5 allows remote code execution if CGI is enabled and a CGI program is dynamically linked. This is a result of initializing the environment of forked CGI scripts using untrusted HTTP request parameters in the cgiHandler function in cgi.c. When combined with the glibc dynamic linker, this behaviour can be abused for remote code execution using special parameter names such as LD_PRELOAD. An attacker can POST their shared object payload in the body of the request, and reference it using /proc/self/fd/0.

Sources

CVSS vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H