CVE 202543857: uninstall net-imap gem (#1480)

* fix: Update net-imap gem to 0.5.7 to resolve CVE-2025-43857 in Linux container build

* fix: Update net-imap gem to 0.5.7 to resolve CVE-2025-43857 in Linux container build

* remove and install net-imap

* removed net-imap

* uninstall net-imap

* Added comment

* Removed gem for windows agent

* Removed net-imap for both windows and linux

Author: suyadav1

kubernetes/linux/setup.sh

@@ -34,6 +34,9 @@ rm -rf /usr/lib/ruby/gems/3.3.0/gems/find-0.2.0
 rm /usr/lib/ruby/gems/3.3.0/specifications/default/rdoc-6.6.3.1.gemspec
 rm -rf /usr/lib/ruby/gems/3.3.0/gems/rdoc-6.6.3.1
 
+# remove net-imap gem as it has a known CVE (CVE-2025-43857) and is not used by the agent
+gem uninstall net-imap --force
+
 sudo tdnf install -y azure-mdsd-1.35.1
 cp -f $TMPDIR/mdsd.xml /etc/mdsd.d
 cp -f $TMPDIR/envmdsd /etc/mdsd.d

kubernetes/windows/Dockerfile

@@ -32,7 +32,9 @@ RUN refreshenv \
 && gem install win32-ipc -v 0.7.0 \
 && gem install win32-event -v 0.6.3 \
 # remove rexml gem to avoid vulnerability
-&& gem uninstall rexml -v 3.2.5 --force\
+&& gem uninstall rexml -v 3.2.5 --force \
+# remove net-imap gem as it has a known CVE (CVE-2025-43857) and is not used by the agent
+&& gem uninstall net-imap --force \
 # The following gems are required for fluentd plugins, or ruby for configuration parsing
 && gem install windows-pr -v 1.2.6 \
 && gem install tomlrb -v 2.0.1 \