TFTP, firmware upgrade, version 1.255, downgrade attack, block number wrap, IoT security.
A. Secura, J. Kim Department of Network Engineering, Cyber-Physical Systems Institute i--- Tftp Upgrade Firmware Version 1.255 Download
Analysis of TFTP-Based Firmware Upgrade Mechanisms: A Case Study of Version 1.255 Download Anomalies TFTP, firmware upgrade, version 1
[1] Sollins, K. RFC 1350 – The TFTP Protocol (Revision 2). 1992. [2] Secura, A. “Firmware Downgrade Attacks in Embedded Networks.” J. IoT Security, vol. 8, 2023. [3] RFC 7440 – TFTP Windowsize and Blocksize Options. [2] Secura, A
| Observation | Implication | |-------------|--------------| | Version string “1.255” passed unverified | Attacker could serve version 1.0 (downgrade) | | TFTP block number overflow after block 65535 | Firmware > 32 MB caused retransmission loops | | No hash exchange before transfer | Man-in-the-middle can inject malicious firmware | | Logs show “i---” but no source MAC validation | Spoofing possible |
