Vulnerability-Lookup

CNVD-2021-39776

Vulnerability from cnvd - Published: 2021-06-06

Title

QEMU权限提升漏洞（CNVD-2021-39776）

Description

QEMU是一套模拟处理器软件。 QEMU存在权限提升漏洞，攻击者可利用该漏洞可以通过QEMU的Virtiofsd Xattrmap选项绕过限制，从而提高在主机系统上的特权。

Severity

低

Formal description

厂商尚未提供漏洞修复方案，请关注厂商主页更新： https://www.qemu.org/

Reference

https://vigilance.fr/vulnerability/QEMU-privilege-escalation-via-Virtiofsd-Xattrmap-Option-34767

Impacted products

Name
QEMU QEMU

Show details on source website

JSON

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{
  "cves": {
    "cve": {
      "cveNumber": "CVE-2021-20263",
      "cveUrl": "https://nvd.nist.gov/vuln/detail/CVE-2021-20263"
    }
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  "description": "QEMU\u662f\u4e00\u5957\u6a21\u62df\u5904\u7406\u5668\u8f6f\u4ef6\u3002\n\nQEMU\u5b58\u5728\u6743\u9650\u63d0\u5347\u6f0f\u6d1e\uff0c\u653b\u51fb\u8005\u53ef\u5229\u7528\u8be5\u6f0f\u6d1e\u53ef\u4ee5\u901a\u8fc7QEMU\u7684Virtiofsd Xattrmap\u9009\u9879\u7ed5\u8fc7\u9650\u5236\uff0c\u4ece\u800c\u63d0\u9ad8\u5728\u4e3b\u673a\u7cfb\u7edf\u4e0a\u7684\u7279\u6743\u3002",
  "formalWay": "\u5382\u5546\u5c1a\u672a\u63d0\u4f9b\u6f0f\u6d1e\u4fee\u590d\u65b9\u6848\uff0c\u8bf7\u5173\u6ce8\u5382\u5546\u4e3b\u9875\u66f4\u65b0\uff1a\r\nhttps://www.qemu.org/",
  "isEvent": "\u901a\u7528\u8f6f\u786c\u4ef6\u6f0f\u6d1e",
  "number": "CNVD-2021-39776",
  "openTime": "2021-06-06",
  "products": {
    "product": "QEMU QEMU"
  },
  "referenceLink": "https://vigilance.fr/vulnerability/QEMU-privilege-escalation-via-Virtiofsd-Xattrmap-Option-34767",
  "serverity": "\u4f4e",
  "submitTime": "2021-03-09",
  "title": "QEMU\u6743\u9650\u63d0\u5347\u6f0f\u6d1e\uff08CNVD-2021-39776\uff09"
}

CVE-2021-20263 (GCVE-0-2021-20263)

Vulnerability from cvelistv5 – Published: 2021-03-09 17:17 – Updated: 2024-08-03 17:37

Summary

A flaw was found in the virtio-fs shared file system daemon (virtiofsd) of QEMU. The new 'xattrmap' option may cause the 'security.capability' xattr in the guest to not drop on file write, potentially leading to a modified, privileged executable in the guest. In rare circumstances, this flaw could be used by a malicious user to elevate their privileges within the guest.

Severity

No CVSS data available.

CWE

CWE-281

Assigner

redhat redhat root

References

4 references

URL	Tags
https://bugzilla.redhat.com/show_bug.cgi?id=1933668	x_refsource_MISC
https://www.openwall.com/lists/oss-security/2021/…	x_refsource_MISC
https://security.netapp.com/advisory/ntap-2021050…	x_refsource_CONFIRM
https://security.gentoo.org/glsa/202208-27	vendor-advisoryx_refsource_GENTOO

Impacted products

1 product

Vendor	Product	Version
n/a	QEMU	Affected: qemu 5.2.50

Show details on NVD website

JSON

To clipboard

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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.