CVE-2020-25624
Description
A flaw was found in QEMU. An out-of-bounds read/write access issue was found in the USB OHCI controller emulator. This issue occurs while servicing transfer descriptors (TD), as the OHCI controller derives variables 'start_addr', 'end_addr', and 'len' from values supplied by the host controller driver. The host controller driver may supply values when using these variables, leading to an out-of-bounds access issue. This flaw allows a guest user or process to crash the QEMU process on the host, resulting in a denial of service.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5 | 5 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | High | High | N/A |
| Privileges Required | High | High | N/A |
| User Interaction | None | None | N/A |
| Scope | Changed | Changed | N/A |
| Confidentiality | Low | Low | N/A |
| Integrity Impact | Low | Low | N/A |
| Availability Impact | Low | Low | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:L
NVD: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:L
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
Write operations could cause memory corruption. In some cases, an adversary can modify control data such as return addresses in order to execute unexpected code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
Attempting to access out-of-range, invalid, or unauthorized memory could cause the product to crash.
Other
Technical Impact: Unexpected State
Subsequent write operations can produce undefined or unexpected results.
Acknowledgements
Red Hat would like to thank Gaoning Pan (Zhejiang university), Yi Ren (Alibaba Cloud Intelligence Security Team), and Yongkang Jia (Zhejiang university) for reporting this issue.
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