System crash or code execution via bad cast
Published Apr 23, 2020 · Updated Sep 16, 2024
Type confusion in shiftfs in Canonical Ubuntu Kernel 5.0 and 5.3 series allows local users to crash the system or execute code. shiftfs_btrfs_ioctl_fd_replace() passes an arbitrary fdget() result to shiftfs_real_fdget(), which treats filesystem-specific private_data as a shiftfs_file_info pointer without validating its type. The demonstrated path requires an unprivileged local user namespace, a shiftfs mount and a crafted Btrfs ioctl; success causes a kernel crash or kernel-context code execution.
Summary
What happened
Type confusion in shiftfs in Canonical Ubuntu Kernel 5.0 and 5.3 series allows local users to crash the system or execute code. shiftfs_btrfs_ioctl_fd_replace() passes an arbitrary fdget() result to shiftfs_real_fdget(), which treats filesystem-specific private_data as a shiftfs_file_info pointer without validating its type. The demonstrated path requires an unprivileged local user namespace, a shiftfs mount and a crafted Btrfs ioctl; success causes a kernel crash or kernel-context code execution.
The record
- CVE
- CVE-2019-15792
- Published
- Apr 23, 2020
- Updated
- Sep 16, 2024
- Vendor
- Canonical
- Product
- Ubuntu Kernel
- Classifications
- CWE-843, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Apr 23, 2020CVE 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=5.0 kernel <5.0.0-35.38
- Affected versionversion=5.3.0-11.12 <5.3 kernel* changes=[{"at":"5.3.0-22.24","status":"unaffected"}]
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.
Weakness, pattern, technique
Public exploit references
- Ubuntu 19.10 Refcount Underflow and Type Confusion in shiftfsproof of concept · validated
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Technologies
Your stack
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Your stack
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