CVE-2021-39828

Local privilege escalation via insecure temporary directory

Published Sep 27, 2021 · Updated Apr 23, 2025

Privilege escalation in the Adobe Digital Editions 4.5.11.187646 and earlier macOS installer allows local users to gain elevated access. The installer creates a temporary file in a directory with permissions that inadequately restrict local access; Adobe does not disclose the file or path. Exploitation requires authenticated local access and user interaction before installation, after which the attacker gains elevated privileges.

CVSS severity5.8
Medium
EPSS probability1.50%
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 the Adobe Digital Editions 4.5.11.187646 and earlier macOS installer allows local users to gain elevated access. The installer creates a temporary file in a directory with permissions that inadequately restrict local access; Adobe does not disclose the file or path. Exploitation requires authenticated local access and user interaction before installation, after which the attacker gains elevated privileges.

The record

CVE
CVE-2021-39828
Published
Sep 27, 2021
Updated
Apr 23, 2025
Vendor
Adobe
Product
Adobe Digital Editions
Classifications
CWE-379, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 27, 2021CVE publishedPublication date reported by the CVE source.
  2. Apr 23, 2025Record 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=unspecified <=4.5.11.187646
  2. Affected versionversion=unspecified <=None

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Adobe · Adobe Digital Editionsversion=unspecified <=4.5.11.187646; version=unspecified <=None

Published CVSS scores

5.8AdobeCVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-379Creation of Temporary File in Directory with Incorrect Permissions
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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