CVE-2021-32826Public exploitNetwork attack vector

Arbitrary command execution via Nashorn sandbox escape

Published Aug 16, 2021 · Updated Aug 3, 2024

Command injection in Proxyee Down allows remote attackers to execute arbitrary commands through a malicious extension script. The extension loader evaluates attacker-supplied JavaScript with Nashorn, whose class-filter sandbox can be bypassed through the engine object's factory to reach java.lang.Runtime.exec. Exploitation requires control of an extension source, such as hosting a malicious extension or intercepting its delivery, and executes commands with the application's privileges.

CVSS severity8.1
High
EPSS probability1.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Command injection in Proxyee Down allows remote attackers to execute arbitrary commands through a malicious extension script. The extension loader evaluates attacker-supplied JavaScript with Nashorn, whose class-filter sandbox can be bypassed through the engine object's factory to reach java.lang.Runtime.exec. Exploitation requires control of an extension source, such as hosting a malicious extension or intercepting its delivery, and executes commands with the application's privileges.

The record

CVE
CVE-2021-32826
Published
Aug 16, 2021
Updated
Aug 3, 2024
Vendor
Proxyee Down
Product
Proxyee Down
Classifications
CWE-78, T1059.007
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 16, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 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?

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

  1. Affected versionversion=all

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Proxyee Down · Proxyee Downversion=all

Published CVSS scores

6.8GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N
8.1NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
9.3NIST NVDAV:N/AC:M/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059.007JavaScript

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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