Privileged shell access via interruptible UART bootloader
Published Sep 23, 2024 · Updated Sep 23, 2024
Improper privilege management in Ubiquiti airMAX Firmware 8 allows physically proximate attackers to gain a privileged command shell. The exposed UART console permits the U-Boot sequence to be interrupted and accepts a bootargs change from init=/init to init=/bin/sh without authentication. Physical access to the circuit board and a serial adapter is required; the resulting one-boot shell can read or alter device data and configuration.
Summary
What happened
Improper privilege management in Ubiquiti airMAX Firmware 8 allows physically proximate attackers to gain a privileged command shell. The exposed UART console permits the U-Boot sequence to be interrupted and accepts a bootargs change from init=/init to init=/bin/sh without authentication. Physical access to the circuit board and a serial adapter is required; the resulting one-boot shell can read or alter device data and configuration.
The record
- CVE
- CVE-2024-44540
- Published
- Sep 23, 2024
- Updated
- Sep 23, 2024
- Vendor
- Ubiquiti
- Product
- airMAX Firmware
- Classifications
- CWE-269, T1059.004
- Attack vector
- physical
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 23, 2024CVE publishedPublication date reported by the CVE source.
- Sep 23, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=8
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- UART login-bypass walkthrough for airMAXfunctional · demonstrated
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Technologies
Your stack
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Your stack
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