Memory corruption via stale segmented Bluetooth buffer
Published Sep 19, 2025 · Updated Sep 19, 2025
Use-after-free in Zephyr RTOS 4.1 and earlier allows physically proximate attackers to corrupt memory through crafted Bluetooth LE traffic. During disconnection, bt_conn_tx_processor frees a net_buf returned by l2cap_pull_data without accounting for segmentation and later writes four attacker-controlled bytes through the stale buffer. Bluetooth LE reachability is required; the corruption can alter memory or interrupt the device, but published evidence does not demonstrate code execution.
Summary
What happened
Use-after-free in Zephyr RTOS 4.1 and earlier allows physically proximate attackers to corrupt memory through crafted Bluetooth LE traffic. During disconnection, bt_conn_tx_processor frees a net_buf returned by l2cap_pull_data without accounting for segmentation and later writes four attacker-controlled bytes through the stale buffer. Bluetooth LE reachability is required; the corruption can alter memory or interrupt the device, but published evidence does not demonstrate code execution.
The record
- CVE
- CVE-2025-7403
- Published
- Sep 19, 2025
- Updated
- Sep 19, 2025
- Vendor
- Zephyr Project
- Product
- Zephyr RTOS
- Classifications
- CWE-123
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 19, 2025CVE publishedPublication date reported by the CVE source.
- Sep 19, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=* <=4.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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