CVE-2023-28646

Metadata disclosure via duplicate activity resume counting

Published Mar 30, 2023 · Updated Feb 11, 2025

Authentication bypass in Nextcloud Android 3.7.0 through 3.24.0 allows attackers to view file-sharing metadata via crafted deep links. A singleTask AuthenticatorActivity invokes PassCodeManager.onActivityResumed from both onResume and onNewIntent, causing one restart to be counted twice and prematurely clearing the app lock. Exploitation requires an unlocked physical Android device and a third-party app; exposure is limited to metadata such as file sharers, sharees, and activity.

CVSS severity4.4
Medium
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Authentication bypass in Nextcloud Android 3.7.0 through 3.24.0 allows attackers to view file-sharing metadata via crafted deep links. A singleTask AuthenticatorActivity invokes PassCodeManager.onActivityResumed from both onResume and onNewIntent, causing one restart to be counted twice and prematurely clearing the app lock. Exploitation requires an unlocked physical Android device and a third-party app; exposure is limited to metadata such as file sharers, sharees, and activity.

The record

CVE
CVE-2023-28646
Published
Mar 30, 2023
Updated
Feb 11, 2025
Vendor
Nextcloud GmbH
Product
Security Advisories
Classifications
CWE-281, CWE-287
Attack vector
physical
Privileges
Unavailable

Timeline

How it unfolded

  1. Mar 30, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 11, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=>= 3.7.0, < 3.24.1

What conditions does exploitation require?

Attack vectorphysical
Required privilegesUnavailable in this record.

What is affected?

Nextcloud GmbH · Security Advisoriesversion=>= 3.7.0, < 3.24.1

Published CVSS scores

4.4GitHub CNACVSS:3.1/AV:P/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:L
3.7GitHub Security AdvisoryCVSS:3.1/AV:P/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:L
2.4NIST NVDCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:L/I:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorphysical
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-281Improper Preservation of Permissions
CWE-287Improper Authentication

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo