Kernel memory disclosure via short bridge skb
Published Jun 19, 2024 · Updated Aug 5, 2026
Uninitialized memory disclosure in the Linux bridge transmit path allows local users to read kernel heap data via a short skb. br_dev_xmit assumes the skb contains an Ethernet header, and br_dev_queue_push_xmit then prepends ETH_HLEN bytes that expose uninitialized headroom on bridge ports. Triggering requires locally creating a network namespace and redirecting a sub-14-byte packet with namespace-scoped network capabilities; insufficient headroom can instead panic the kernel.
Summary
What happened
Uninitialized memory disclosure in the Linux bridge transmit path allows local users to read kernel heap data via a short skb. br_dev_xmit assumes the skb contains an Ethernet header, and br_dev_queue_push_xmit then prepends ETH_HLEN bytes that expose uninitialized headroom on bridge ports. Triggering requires locally creating a network namespace and redirecting a sub-14-byte packet with namespace-scoped network capabilities; insufficient headroom can instead panic the kernel.
The record
- CVE
- CVE-2024-38538
- Published
- Jun 19, 2024
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1005
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 19, 2024CVE publishedPublication date reported by the CVE source.
- Aug 5, 2026Record 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <1abb371147905ba250b4cc0230c4be7e90bea4d5
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <28126b83f86ab9cc7936029c2dff845d3dcedba2
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <3e01fc3c66e65d9afe98f1489047a1b2dd8741ca
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <5b5d669f569807c7ab07546e73c0741845a2547a
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <82090f94c723dab724b1c32db406091d40448a17
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8bd67ebb50c0145fd2ca8681ab65eb7e8cde1afc
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b2b7c43cd32080221bb233741bd6011983fe7c11
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c964429ef53f42098a6545a5dabeb1441c1e821d
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f482fd4ce919836a49012b2d31b00fc36e2488f2
- Affected versionversion=2.6.12
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Technologies
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