VulnerabilityPublished 5 Nov 2025

CVE-2025-20376: Unrestricted File Upload

Source GCVE Database

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Authoritative record:CVE-2025-20376· Medium 6.5

Not known to be exploited · CVSS 6.5 Medium.

Data as of 4 Nov 2026, 18:11 UTC

CVSS 3.1 base score

6.5Medium

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CNA (cisco)	CVSS 3.1	6.5

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: High
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 5 Nov 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 4 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-x3h8-2mvf-vv78

What to do

Affected software

Product	Affected	Fixed in
CiscoCisco Unified Contact Center Express	Affected 10.5(1) – UCCX 15.0.1 57 affected builds	Fixed in–

AI-suggested

Since the vulnerability requires valid administrative credentials, organizations should ensure strong credential management and restrict administrative access. Monitor vendor advisories for updates and apply patches promptly once released.

Description

CVE-2025-20376 is a vulnerability in the web UI of Cisco Unified CCX that allows an authenticated remote attacker with administrative credentials to upload and execute arbitrary files. This occurs due to insufficient input validation in the file upload mechanism, enabling command execution and privilege escalation to root.

Impact

Successful exploitation allows an authenticated attacker with administrative privileges to execute arbitrary commands on the system hosting Cisco Unified CCX and escalate privileges to root. This compromises system confidentiality and integrity but does not affect availability. The attack requires valid administrative credentials, limiting the threat to insiders or compromised accounts.

Summary

This vulnerability affects the web UI of Cisco Unified CCX and stems from insufficient input validation related to file uploads. An attacker with valid administrative credentials can exploit this flaw by uploading a malicious file through the web interface, leading to arbitrary command execution on the underlying system and elevation of privileges to root. The CVSS 3.1 base score is 6.5, indicating a medium severity impact with network attack vector, low attack complexity, high privileges required, no user interaction, and high confidentiality and integrity impact but no availability impact. There is no indication of known exploits in the wild or available patches at this time.

CWE-434Unrestricted Upload of File with Dangerous Type (opens in a new tab)
Base weaknessLikelihood of exploit: MediumCWE Top 25 (2025): #12OWASP Top 10 A06:2025: Insecure Design (opens in a new tab)
The product allows the upload or transfer of dangerous file types that are automatically processed within its environment.
Architecture and Design
Generate a new, unique filename for an uploaded file instead of using the user-supplied filename, so that no external input is used at all.
Architecture and Design · Enforcement by Conversion
When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs.
Architecture and Design
Consider storing the uploaded files outside of the web document root entirely. Then, use other mechanisms to deliver the files dynamically.
OWASP Cheat Sheets
Server Side Request Forgery Prevention (opens in a new tab)
Web Service Security (opens in a new tab)
Third Party Javascript Management (opens in a new tab)
File Upload (opens in a new tab)
Secure Design Principles (opens in a new tab)
OWASP ASVS 4.0.3
V12.5.2 (opens in a new tab)
V13.1.5 (opens in a new tab)
V12.2.1 (opens in a new tab)
Attack patterns
Accessing Functionality Not Properly Constrained by ACLs (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 4 Nov 2026, 18:11 UTC

WeaknessesCWE-434

Technical details

References

Community reviews

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