Container escape via shared-volume mount race
Published Feb 12, 2020 · Updated Aug 5, 2024
Mount race in Open Container Initiative runc 1.0.0-rc9 and earlier allows local users to escape a container and modify the host. During mountToRootfs, mount(2) follows a rootfs /proc symlink while a second container swaps a shared-volume path, so later remounts target attacker-controlled locations. Exploitation requires control of two custom container images and their shared-volume mounts; successful races bypass procfs masking and security labels, enabling writes to host paths.
Summary
What happened
Mount race in Open Container Initiative runc 1.0.0-rc9 and earlier allows local users to escape a container and modify the host. During mountToRootfs, mount(2) follows a rootfs /proc symlink while a second container swaps a shared-volume path, so later remounts target attacker-controlled locations. Exploitation requires control of two custom container images and their shared-volume mounts; successful races bypass procfs masking and security labels, enabling writes to host paths.
The record
- CVE
- CVE-2019-19921
- Published
- Feb 12, 2020
- Updated
- Aug 5, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-706, T1611
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 12, 2020CVE publishedPublication date reported by the CVE source.
- Aug 5, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Public exploit references
- Minimal runc shared-volume race proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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