CVE-2021-41181

Chat and file disclosure via missing keyguard check

Published Mar 8, 2022 · Updated Apr 23, 2025

Authentication bypass in Nextcloud Talk for Android before 12.3.0 allows physically proximate attackers to read chat messages and files. The incoming-call notification path lets the in-call chat view open without reasserting Android's keyguard while the phone remains locked. Physical access to a locked device and receipt of a call are required; exposure is limited to data available through the victim's Talk session.

CVSS severity2.4
Low
EPSS probability0.31%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Nextcloud Talk for Android before 12.3.0 allows physically proximate attackers to read chat messages and files. The incoming-call notification path lets the in-call chat view open without reasserting Android's keyguard while the phone remains locked. Physical access to a locked device and receipt of a call are required; exposure is limited to data available through the victim's Talk session.

The record

CVE
CVE-2021-41181
Published
Mar 8, 2022
Updated
Apr 23, 2025
Vendor
Nextcloud GmbH
Product
Security Advisories
Classifications
CWE-287, CWE-288, CWE-200, T1409
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 8, 2022CVE 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=< 12.3.0

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

Nextcloud GmbH · Security Advisoriesversion=< 12.3.0

Published CVSS scores

2.1NIST NVDAV:L/AC:L/Au:N/C:P/I:N/A:N
2.4GitHub, Inc.CVSS: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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication
CWE-288Authentication Bypass Using an Alternate Path or Channel
CWE-200Exposure of Sensitive Information to an Unauthorized Actor
T1409Access Stored Application Data

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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