CVE-2025-8021VulnerabilityPublished 23 Jul 2025

CVE-2025-8021: files-bucket-server · Directory Traversal

Affects files-bucket-serverSource CVE Database V5

Not known to be exploited · CVSS 8.7 High.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 4.0 base score

8.7High

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

EPSS: 0.7% chance of exploitation in 30 days – higher than 54% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P

Base metrics

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: High
Vulnerable system integrity: None
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Threat metrics

Exploit Maturity: POC

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

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, 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: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: High: There is a total loss of confidentiality, resulting in all information within the Vulnerable System being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.
Exploit Maturity: POC: Based on threat intelligence sources each of the following must apply: · Proof-of-concept is publicly available · No knowledge of reported attempts to exploit this vulnerability · No knowledge of publicly available solutions used to simplify attempts to exploit the vulnerability

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 23 Jul 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 2026-10-26.

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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC 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.

What to do

Affected software

Product	Affected	Fixed in
npmfiles-bucket-server`pkg:npm/files-bucket-server`Other threats	Affected =0	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Immediate mitigation should focus on restricting external access to the files-bucket-server instances through network segmentation and firewall rules, limiting exposure to trusted internal networks only. Organizations should monitor and audit access logs for suspicious file access patterns indicative of traversal attempts. Since no patches are currently available, consider deploying Web Application Firewalls (WAFs) with custom rules to detect and block directory traversal payloads such as '../' sequences in requests. Implement strict input validation and sanitization on any user-supplied file path parameters if customization or updates to the software are possible. Where feasible, isolate the files-bucket-server in containerized or sandboxed environments with minimal privileges and limited file system access to contain potential exploitation. Organizations should also prepare for patch deployment once available by tracking vendor advisories and subscribing to vulnerability feeds. Conducting penetration testing focused on directory traversal and file access controls can help identify exposure and validate mitigations.

Description

All versions of the package files-bucket-server are vulnerable to Directory Traversal where an attacker can traverse the file system and access files outside of the intended directory.

Impact

For European organizations, the impact of CVE-2025-8021 can be substantial. Unauthorized file system access could lead to exposure of sensitive personal data protected under GDPR, resulting in regulatory penalties and reputational damage. Organizations relying on files-bucket-server for internal or external file storage risk data breaches that compromise confidentiality. Attackers could extract configuration files, private keys, or other sensitive assets, enabling further lateral movement or persistent access. Critical sectors such as finance, healthcare, and government agencies in Europe could face operational disruptions if sensitive data is leaked or manipulated. Additionally, the breach of confidential information could undermine trust with customers and partners. Given the vulnerability requires no authentication and is remotely exploitable, attackers could target exposed servers directly, increasing the risk of widespread exploitation if the software is widely deployed without mitigation.

References

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