Out-of-bounds IPv6 access via unchecked IPHC header length
Published Oct 12, 2021 · Updated Sep 16, 2024
Integer underflow in Zephyr RTOS 2.4.0 and later before 2.5.0 allows remote attackers to trigger out-of-bounds IPv6 parsing via 6LoWPAN packets. In uncompress_IPHC_header, a packet-controlled compressed header size is passed to net_buf_pull without verifying that the first buffer fragment contains that many bytes, underflowing its unsigned length and moving its data pointer out of bounds. No privileges or user interaction are required, but the target must process a malformed packet through a 6LoWPAN path such as Bluetooth, CAN bus, or IEEE 802.15.4; subsequent IPv6 handling accesses memory outside the valid network buffer.
Summary
What happened
Integer underflow in Zephyr RTOS 2.4.0 and later before 2.5.0 allows remote attackers to trigger out-of-bounds IPv6 parsing via 6LoWPAN packets. In uncompress_IPHC_header, a packet-controlled compressed header size is passed to net_buf_pull without verifying that the first buffer fragment contains that many bytes, underflowing its unsigned length and moving its data pointer out of bounds. No privileges or user interaction are required, but the target must process a malformed packet through a 6LoWPAN path such as Bluetooth, CAN bus, or IEEE 802.15.4; subsequent IPv6 handling accesses memory outside the valid network buffer.
The record
- CVE
- CVE-2021-3323
- Published
- Oct 12, 2021
- Updated
- Sep 16, 2024
- Vendor
- Zephyr Project
- Product
- Zephyr RTOS
- Classifications
- CWE-191
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 12, 2021CVE publishedPublication date reported by the CVE source.
- Sep 16, 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?
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- Affected versionversion=>=2.4.0 <unspecified
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What is affected?
Published CVSS scores
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Attacks
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Technologies
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Your stack
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