Release Notes for StarOS™ Software Version 21.23.5 - Cisco
: Technical patches for hardware like the ASR 5000 should only be obtained directly from the Cisco Software Download portal to ensure authenticity. 21398.rar
While the number matches a known Cisco software bug, .rar files with generic numeric names (like 21398.rar) are frequently used on third-party file-sharing sites to distribute potentially harmful content or cracked software. Release Notes for StarOS™ Software Version 21