Service interruption via wrapped MultiDRM heap allocation
Published Aug 9, 2022 · Updated Aug 4, 2024
Heap buffer overflow in Huawei EMUI, Magic UI, and HarmonyOS allows attackers to interrupt availability through crafted DRM input. MDrm_TA_CMD_OEMCrypto_LoadEntitledContentKeys wraps a user-controlled key count when sizing an allocation, then uses the original count to copy eight words per loop into the undersized buffer. Access to the trusted application is restricted to whitelisted local DRM services; the demonstrated path required kernel patching on a P40 Pro and caused a trustlet crash with controlled memory overwrite.
Summary
What happened
Heap buffer overflow in Huawei EMUI, Magic UI, and HarmonyOS allows attackers to interrupt availability through crafted DRM input. MDrm_TA_CMD_OEMCrypto_LoadEntitledContentKeys wraps a user-controlled key count when sizing an allocation, then uses the original count to copy eight words per loop into the undersized buffer. Access to the trusted application is restricted to whitelisted local DRM services; the demonstrated path required kernel patching on a P40 Pro and caused a trustlet crash with controlled memory overwrite.
The record
- CVE
- CVE-2021-40034
- Published
- Aug 9, 2022
- Updated
- Aug 4, 2024
- Vendor
- MindSpore
- Product
- HarmonyOS
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Aug 9, 2022CVE publishedPublication date reported by the CVE source.
- Aug 4, 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?
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- Affected versionversion=2.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
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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
No sourced classifications are available.
Public exploit references
- MultiDRM LoadEntitledContentKeys heap-overflow proof of conceptfunctional · demonstrated
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Technologies
Your stack
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Your stack
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