CVE-2021-20181
QEMU Plan 9 File System Time-Of-Check Time-Of-Use Privilege Escalation Vulnerability
Severity Score
Exploit Likelihood
Affected Versions
Public Exploits
0Exploited in Wild
-Decision
Descriptions
A race condition flaw was found in the 9pfs server implementation of QEMU up to and including 5.2.0. This flaw allows a malicious 9p client to cause a use-after-free error, potentially escalating their privileges on the system. The highest threat from this vulnerability is to confidentiality, integrity as well as system availability.
Se encontró un fallo de condición de carrera en la implementación del servidor 9pfs de QEMU versiones hasta 5.2.0 incluyéndola. Este fallo permite a un cliente 9p malicioso causar un error de uso de la memoria previamente liberada, escalando potencialmente sus privilegios en el sistema. La mayor amenaza de esta vulnerabilidad es la confidencialidad, la integridad así como la disponibilidad del sistema
This vulnerability allows local attackers to execute arbitrary code on affected installations of QEMU. An attacker must first obtain the ability to execute high-privileged code on the target guest system in order to exploit this vulnerability.
The specific flaw exists within the handling of file descriptor maps. The issue results from the lack of proper locking when performing operations on an object. An attacker can leverage this vulnerability to escalate privileges and execute code in the context of the hypervisor.
CVSS Scores
SSVC
- Decision:-
Timeline
- 2020-12-17 CVE Reserved
- 2021-02-08 CVE Published
- 2023-03-08 EPSS Updated
- 2024-08-03 CVE Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
- ---------- First Exploit
CWE
- CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
- CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition
CAPEC
References (5)
| URL | Tag | Source |
|---|---|---|
| https://lists.debian.org/debian-lts-announce/2021/02/msg00024.html | Mailing List |
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| https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html | Mailing List |
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| https://security.netapp.com/advisory/ntap-20210720-0009 | Third Party Advisory |
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| https://www.zerodayinitiative.com/advisories/ZDI-21-159 | Third Party Advisory |
|
| URL | Date | SRC |
|---|
| URL | Date | SRC |
|---|---|---|
| https://bugzilla.redhat.com/show_bug.cgi?id=1927007 | 2023-11-07 |
| URL | Date | SRC |
|---|
Affected Vendors, Products, and Versions
| Vendor | Product | Version | Other | Status | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Vendor | Product | Version | Other | Status | <-- --> | Vendor | Product | Version | Other | Status |
| Qemu Search vendor "Qemu" | Qemu Search vendor "Qemu" for product "Qemu" | <= 5.2.0 Search vendor "Qemu" for product "Qemu" and version " <= 5.2.0" | - |
Affected
| ||||||
| Debian Search vendor "Debian" | Debian Linux Search vendor "Debian" for product "Debian Linux" | 9.0 Search vendor "Debian" for product "Debian Linux" and version "9.0" | - |
Affected
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| Debian Search vendor "Debian" | Debian Linux Search vendor "Debian" for product "Debian Linux" | 10.0 Search vendor "Debian" for product "Debian Linux" and version "10.0" | - |
Affected
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