SAS/Intrnet 9.4 build 1520 and earlier allows Local File Inclusion. The samples library (included by default) in the appstart.sas file, allows end-users of the application to access the sample.webcsf1.sas program, which contains user-controlled macro variables that are passed to the DS2CSF macro. Users can escape the context of the configured user-controllable variable and append additional functions native to the macro but not included as variables within the library. This includes a function that retrieves files from the host OS.

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-41569
• https://support.sas.com/kb/68/641.html
• https://www.mindpointgroup.com/blog/high-risk-vulnerability-discovery-localfileinclusion-sas