CVE-2021-3947 is a medium severity vulnerability affecting the QEMU NVMe component. This vulnerability allows a malicious guest controlling certain inputs to exploit a stack-buffer overflow found in the function nvme_changed_nslist(). The flaw enables the attacker to read out-of-bounds memory, potentially leading to sensitive information disclosure. Given the implications of this vulnerability, organizations using affected versions of QEMU should take immediate steps to address it.
The CVSS score for this vulnerability is 5.5, indicating a medium level of risk. The attack vector is local, and the complexity is low, meaning that an attacker needs only low privileges to exploit this vulnerability without requiring user interaction. As such, organizations should prioritize patching this vulnerability to mitigate the risk of exploitation.
The urgency of addressing this vulnerability is heightened by its potential impact on confidentiality, which is rated as high. Organizations should ensure that they are aware of the systems affected and the implications of exploitation, as this could lead to significant security breaches.
It is important to confirm whether the vulnerability is actively being exploited in the wild. Currently, there are no public exploits available, but the presence of proof-of-concept code on platforms like GitHub indicates that knowledge about this vulnerability is circulating among malicious actors.
Organizations should prioritize patching immediately. The potential for sensitive data exposure necessitates swift action to mitigate this risk.
Vulnerability Details
CVE-2021-3947 was published on February 18, 2022. The flaw was identified in QEMU's NVMe component, specifically in the nvme_changed_nslist() function. The vulnerability is classified under CWE-125 (Out-of-bounds Read). The CVSS v3.1 vector string for this vulnerability is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N. The affected versions of QEMU include versions from 6.0.0 to 6.1.0 and specific release candidates of version 6.2.0.
Technical Analysis
The root cause of the vulnerability is a stack-buffer overflow in the nvme_changed_nslist() function. This flaw allows a malicious actor to control specific inputs, which can result in the reading of out-of-bounds memory. The attack vector is local, and the complexity of the attack is low. Privileges required are classified as low, and user interaction is not needed. The vulnerability impacts confidentiality, integrity, and availability as follows: confidentiality impact is high, integrity impact is none, and availability impact is none.
Risk & Impact Analysis
The risk to organizations includes potential exposure of sensitive information due to unauthorized access via the vulnerability. Given the high confidentiality impact, the potential for data breaches is significant. Organizations utilizing affected QEMU versions should take immediate steps to mitigate this vulnerability, particularly in environments where sensitive data is handled.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | Yes |
Public PoC | Yes |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions of QEMU include all versions from 6.0.0 to 6.1.0, as well as version 6.2.0 release candidates rc0 and rc1.
Mitigation & Remediation
To address CVE-2021-3947, organizations should apply patches provided by the QEMU project immediately. If patches are not available, organizations should consider implementing workarounds to mitigate the risk. Configuration hardening and network controls can also help limit exposure. Continuous monitoring of systems for abnormal behavior is recommended to catch any exploitation attempts or anomalies.
Detection Guidance
Organizations should monitor logs for any indicators of exploitation attempts, such as unusual memory access patterns or unauthorized access attempts. Behavioral anomalies in the NVMe component should be flagged for further investigation, along with network signatures that may indicate attempts to exploit this vulnerability.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2021-3947 lies in its representation of vulnerabilities that can arise in complex software systems like QEMU. The pattern of vulnerabilities in hypervisors and virtualization technologies signifies a need for enhanced security practices in development and deployment. Security teams should learn from this incident by prioritizing security assessments and adopting proactive measures to safeguard against similar vulnerabilities.
Organizations can enhance their security posture by implementing a robust vulnerability management program. For continuous improvement, engaging in vulnerability management will help identify and remediate weaknesses proactively.
Additionally, organizations should consider adopting a continuous security testing approach to ensure ongoing protection against emerging threats. This can be achieved through continuous penetration testing that regularly assesses the security posture of systems and applications.
In light of CVE-2021-3947, organizations should also engage in red teaming exercises to simulate attacks and uncover potential vulnerabilities in their defenses.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
.webp)