Bug ID 2064413: UCS file download failure via REST AP

Last Modified: Nov 25, 2025

Affected Product(s):
BIG-IP TMOS(all modules)

Known Affected Versions:
15.1.0, 15.1.0.1, 15.1.0.2, 15.1.0.3, 15.1.0.4, 15.1.0.5, 15.1.1, 15.1.2, 15.1.2.1, 15.1.3, 15.1.3.1, 15.1.4, 15.1.4.1, 15.1.5, 15.1.5.1, 15.1.6, 15.1.6.1, 15.1.7, 15.1.8, 15.1.8.1, 15.1.8.2, 15.1.9, 15.1.9.1, 15.1.10, 15.1.10.2, 15.1.10.3, 15.1.10.4, 15.1.10.5, 15.1.10.6, 15.1.10.7, 15.1.10.8, 16.1.0, 16.1.1, 16.1.2, 16.1.2.1, 16.1.2.2, 16.1.3, 16.1.3.1, 16.1.3.2, 16.1.3.3, 16.1.3.4, 16.1.3.5, 16.1.4, 16.1.4.1, 16.1.4.2, 16.1.4.3, 16.1.5, 16.1.5.1, 16.1.5.2, 16.1.6, 16.1.6.1, 17.1.0, 17.1.0.1, 17.1.0.2, 17.1.0.3, 17.1.1, 17.1.1.1, 17.1.1.2, 17.1.1.3, 17.1.1.4, 17.1.2, 17.1.2.1, 17.1.2.2, 17.1.3

Fixed In:
21.0.0

Opened: Sep 22, 2025

Severity: 2-Critical

Symptoms

When downloading UCS files using the BIG-IP REST API with clients such as PowerShell 7, downloaded files are larger than expected and contain duplicate or corrupted data. The MD5 checksum of the downloaded file does not match the source UCS file on the BIG-IP system.

Impact

UCS file downloads via REST API are incomplete and corrupted. MD5 checksum mismatch prevents UCS archive validation or restore. Automated backups or migrations using REST API may fail. Potential risk of data loss if corrupted UCS files are used for restore.

Conditions

Downloading UCS files over the REST API (using HTTP Range headers) from BIG-IP. Most commonly seen when using PowerShell 7 and other clients that download files in chunks. Not observed with PowerShell 5 or when using SCP/SFTP.

Workaround

Use alternate file transfer methods such as SCP or SFTP to download UCS files directly from /var/local/ucs/ on the BIG-IP system.

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips