CVE-2018-7550
Description
Quick Emulator (QEMU), compiled with the PC System Emulator with multiboot feature support, is vulnerable to an OOB r/w memory access issue. The issue could occur while loading a kernel image during the guest boot, if mh_load_end_addr address is greater than the mh_bss_end_addr address. A user or process could use this flaw to potentially achieve arbitrary code execution on a host.
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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.8 | 8.8 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | High | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Changed | Changed | N/A |
| Confidentiality | High | High | N/A |
| Integrity Impact | High | High | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CVSS v2 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.2 | 4.6 | N/A |
| Attack Vector | Local | Local | N/A |
| Access Complexity | High | Low | N/A |
| Authentication | None | None | N/A |
| Confidentiality Impact | Complete | Partial | N/A |
| Integrity Impact | Complete | Partial | N/A |
| Availability Impact | Complete | Partial | N/A |
Vector
Red Hat: AV:L/AC:H/Au:N/C:C/I:C/A:C
NVD: AV:L/AC:L/Au:N/C:P/I:P/A:P
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 CERT-CC (Orange.com) and Cyrille Chatras (Orange.com) for reporting this issue.
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