CVE-2020-23793Public exploitNetwork attack vector

Guest VM restart via oversized handshake header

Published Aug 22, 2023 · Updated Oct 3, 2024

Improper input validation in Red Hat spice-server 0.14.0-6.el7_6.1 allows remote attackers to restart a guest VM over TCP. The published proof of concept places 0xF0E70000 in the SPICE handshake size field and attributes stream-processing deadlock to async_read_handler. Red Hat's test of the exact cited build rejected that size while the VM kept running, and the maintainer states that the protective handshake check predates 0.14.0.

CVSS severity8.6
High
EPSS probability0.84%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Red Hat spice-server 0.14.0-6.el7_6.1 allows remote attackers to restart a guest VM over TCP. The published proof of concept places 0xF0E70000 in the SPICE handshake size field and attributes stream-processing deadlock to async_read_handler. Red Hat's test of the exact cited build rejected that size while the VM kept running, and the maintainer states that the protective handshake check predates 0.14.0.

The record

CVE
CVE-2020-23793
Published
Aug 22, 2023
Updated
Oct 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-862, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 22, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.6NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-862Missing Authorization
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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