Related Vulnerabilities: CVE-2021-29425  

In Apache Commons IO before 2.7, When invoking the method FileNameUtils.normalize with an improper input string, like "//../foo", or "\\..\foo", the result would be the same value, thus possibly providing access to files in the parent directory, but not further above (thus "limited" path traversal), if the calling code would use the result to construct a path value.

Severity Medium

Remote Yes

Type Directory traversal

Description

In Apache Commons IO before 2.7, When invoking the method FileNameUtils.normalize with an improper input string, like "//../foo", or "\\..\foo", the result would be the same value, thus possibly providing access to files in the parent directory, but not further above (thus "limited" path traversal), if the calling code would use the result to construct a path value.

AVG-1805 java-commons-io 2.6-2 Medium Vulnerable

https://www.openwall.com/lists/oss-security/2021/04/12/1
https://issues.apache.org/jira/browse/IO-556