CVE-2020-17380
Description
A flaw was found in QEMU. A heap-based buffer overflow vulnerability was found in the SDHCI device emulation support allowing a guest user or process to crash the QEMU process on the host resulting in a denial of service condition, or potentially execute arbitrary code with privileges of the QEMU process on the host. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
Statement
This flaw did not affect the following versions of QEMU as they did not include support for SDHCI device emulation:
qemu-kvm-maas shipped with Red Hat Enterprise Linux 7.qemu-kvm-rhevas shipped with Red Hat Virtualization and Red Hat OpenStack.qemu-kvmas shipped with Red Hat Enterprise Linux 6, 7, 8, and RHEL Advanced Virtualization.
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 | 5.7 | 6.3 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | High | Low | 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:L/PR:H/UI:N/S:C/C:L/I:L/A:L
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L
Understanding the Weakness (CWE)
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands; Modify Memory
If the memory accessible by the attacker can be effectively controlled, it may be possible to execute arbitrary code, as with a standard buffer overflow. If the attacker can overwrite a pointer's worth of memory (usually 32 or 64 bits), they can alter the intended control flow by redirecting a function pointer to their own malicious code. Even when the attacker can only modify a single byte arbitrary code execution can be possible. Sometimes this is because the same problem can be exploited repeatedly to the same effect. Other times it is because the attacker can overwrite security-critical application-specific data -- such as a flag indicating whether the user is an administrator.
Availability,Confidentiality
Technical Impact: Read Memory; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)
Out of bounds memory access will very likely result in the corruption of relevant memory, and perhaps instructions, possibly leading to a crash. Other attacks leading to lack of availability are possible, including putting the program into an infinite loop.
Confidentiality
Technical Impact: Read Memory
In the case of an out-of-bounds read, the attacker may have access to sensitive information. If the sensitive information contains system details, such as the current buffer's position in memory, this knowledge can be used to craft further attacks, possibly with more severe consequences.
Acknowledgements
Red Hat would like to thank Alexander Bulekov for reporting this issue.
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