CVE-2020-10027

Kernel privilege escalation via signed syscall comparison

Published May 11, 2020 · Updated Sep 16, 2024

Privilege escalation in Zephyr RTOS 1.14.0 through 1.14.1 and 2.1.0 on ARC allows local users to execute code in the kernel. The ARC syscall entry path uses a signed branch-less-than comparison for a user-controlled syscall number, so a negative value passes the upper-bound check. Code execution in an unprivileged user thread on an ARC build with userspace isolation is required, after which the caller gains kernel privileges.

CVSS severity7.8
High
EPSS probability0.69%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Privilege escalation in Zephyr RTOS 1.14.0 through 1.14.1 and 2.1.0 on ARC allows local users to execute code in the kernel. The ARC syscall entry path uses a signed branch-less-than comparison for a user-controlled syscall number, so a negative value passes the upper-bound check. Code execution in an unprivileged user thread on an ARC build with userspace isolation is required, after which the caller gains kernel privileges.

The record

CVE
CVE-2020-10027
Published
May 11, 2020
Updated
Sep 16, 2024
Vendor
Zephyr Project
Product
Zephyr RTOS
Classifications
CWE-697, T1068
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. May 11, 2020CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.14.0 <unspecified
  2. Affected versionversion=2.1.0 <unspecified

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

Zephyr Project · Zephyr RTOSversion=1.14.0 <unspecified; version=2.1.0 <unspecified

Published CVSS scores

7.8Zephyr ProjectCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.2NIST NVDAV:L/AC:L/Au:N/C:C/I:C/A:C

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-697Incorrect Comparison
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

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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