Host crash via unchecked PPTP frame length
Published Aug 19, 2025 · Updated Aug 5, 2026
Use of uninitialized data in Linux kernel PPTP support allows remote attackers to crash the host via a short tunneled PPP frame. The pptp_xmit() path reads three protocol and LCP bytes from an skb without first ensuring that its linear data contains them, and a later skb_pull() can violate buffer length invariants. Reachability requires an active bridged PPP tunnel whose peer can supply undersized frames; the resulting kernel BUG can panic the host.
Summary
What happened
Use of uninitialized data in Linux kernel PPTP support allows remote attackers to crash the host via a short tunneled PPP frame. The pptp_xmit() path reads three protocol and LCP bytes from an skb without first ensuring that its linear data contains them, and a later skb_pull() can violate buffer length invariants. Reachability requires an active bridged PPP tunnel whose peer can supply undersized frames; the resulting kernel BUG can panic the host.
The record
- CVE
- CVE-2025-38574
- Published
- Aug 19, 2025
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-908, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 19, 2025CVE 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 <1a04db0fd75cb6034fc27a56b67b3b8b9022a98c
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <26672f1679b143aa34fca0b6046b7fd0c184770d
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <5005d24377378a20e5c0e53052fc4ebdcdcbc611
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <504cc4ab91073d2ac7404ad146139f86ecee7193
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <5de7513f38f3c19c0610294ee478242bea356f8c
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <97b8c5d322c5c0038cac4bc56fdbe237d0be426f
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b7dcda76fd0615c0599c89f36873a6cd48e02dbb
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <de9c4861fb42f0cd72da844c3c34f692d5895b7b
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ea99b88b1999ebcb24d5d3a6b7910030f40d3bba
- Affected versionversion=2.6.12
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
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Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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