Interpreter crash via overlong unmount path comparison
Published Sep 17, 2024 · Updated Sep 17, 2024
Heap buffer over-read in MicroPython 1.23.0 allows remote attackers to crash the interpreter through a crafted VFS unmount path. In extmod/vfs.c, mp_vfs_umount passes the requested path length plus one to memcmp without confirming that the stored mount path is equally long, so the comparison reads beyond the stored string. The attacker must be able to execute MicroPython code that mounts a VFS and calls os.umount; the published proof of concept demonstrates an interpreter crash.
Summary
What happened
Heap buffer over-read in MicroPython 1.23.0 allows remote attackers to crash the interpreter through a crafted VFS unmount path. In extmod/vfs.c, mp_vfs_umount passes the requested path length plus one to memcmp without confirming that the stored mount path is equally long, so the comparison reads beyond the stored string. The attacker must be able to execute MicroPython code that mounts a VFS and calls os.umount; the published proof of concept demonstrates an interpreter crash.
The record
- CVE
- CVE-2024-8946
- Published
- Sep 17, 2024
- Updated
- Sep 17, 2024
- Vendor
- MicroPython
- Product
- MicroPython
- Classifications
- CWE-787, CWE-122, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 17, 2024CVE publishedPublication date reported by the CVE source.
- Sep 17, 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=1.23.0
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
- MicroPython VFS unmount proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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