CVE-2021-41181 | Nextcloud Talk app exposes chat messages on lockscreen

Nextcloud talk is a self hosting messaging service. In versions prior to 12.3.0 the Nextcloud Android Talk application did not properly detect the lockscreen state when a call was incoming. If an attacker got physical access to the locked phone, and the victim received a phone call the attacker could gain access to the chat messages and files of the user. It is recommended that the Nextcloud Android Talk App is upgraded to 12.3.0. There are no known workarounds.

Published: 2022-03-08 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-41181 is rated Low Risk (17.2/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.30%). Mandatory action: Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-41181

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.05% 0.30% +0.25%
2 2025-04-06 0.16% 0.05% -0.11%
3 2025-04-04 0.16%

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-41181

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
2.4 3.1 LOW
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:P)
Hands-on access—USB, keyboard, opening the case—not something you do purely over the wire.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
0.9 1.4 [email protected]
2.4 3.1 LOW
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:P)
Hands-on access—USB, keyboard, opening the case—not something you do purely over the wire.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
0.9 1.4 [email protected]
2.1 2.0 LOW
AV:L/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
3.9 2.9 [email protected]

Weakness enumeration for CVE-2021-41181

Affected software / configurations for CVE-2021-41181

Vendor Product Version Raw CPE
nextcloud talk < 12.3.0 cpe:2.3:a:nextcloud:talk:*:*:*:*:*:android:*:*

References for CVE-2021-41181

cvelogic Threat Intelligence