CVE-2023-39957 | Path traversal allows tricking the Talk Android app into writing files into it's root directory

Nextcloud Talk Android allows users to place video and audio calls through Nextcloud on Android. Prior to version 17.0.0, an unprotected intend allowed malicious third party apps to trick the Talk Android app into writing files outside of its intended cache directory. Nextcloud Talk Android version 17.0.0 has a patch for this issue. No known workarounds are available.

Published: 2023-08-10 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-39957 is rated Moderate Risk (54.1/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.48%). Review affected assets and schedule remediation.

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-2023-39957

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 2026-05-05 0.41% 0.48% +0.07%
2 2026-03-04 0.07% 0.41% +0.34%
3 2026-03-01 — 0.07% —

Full EPSS history (35 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-39957

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]
7.2 3.0 HIGH
CVSS:3.0/AV:L/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 0.6 6.0 [email protected]

Weakness enumeration for CVE-2023-39957

Affected software / configurations for CVE-2023-39957

Vendor Product Version Raw CPE
nextcloud talk < 17.0.0 cpe:2.3:a:nextcloud:talk:*:*:*:*:*:android:*:*
nextcloud talk 17.0.0 cpe:2.3:a:nextcloud:talk:17.0.0:rc1:*:*:*:android:*:*
nextcloud talk 17.0.0 cpe:2.3:a:nextcloud:talk:17.0.0:rc2:*:*:*:android:*:*
nextcloud talk 17.0.0 cpe:2.3:a:nextcloud:talk:17.0.0:rc3:*:*:*:android:*:*

References for CVE-2023-39957

cvelogic Threat Intelligence