VulnerabilityPublished 17 Sep 2025Updated 30 Sep 2025

CVE-2025-35430: CISA Thorium · Path Traversal

Affects CISA ThoriumSource CVE Database V5

Not known to be exploited · CVSS 5.0 Medium · fixed in 1.1.2 : update CISA Thorium when convenient.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

5.0Medium

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 41% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.1.2

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Changed
Confidentiality: None
Integrity: Low
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: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on 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 17 Sep 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 26 Oct 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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.

What to do

Affected software

Product	Affected	Fixed in
CISA Thorium	Affected =1.0.0	Fixed in–

AI-suggested

European organizations should immediately upgrade CISA Thorium to version 1.1.2 or later where the vulnerability is fixed. Until the upgrade is possible, organizations should restrict access to the affected functions ('download_ephemeral' and 'download_children') to trusted users only and implement strict access controls and monitoring on file system access. Employ application-layer firewalls or intrusion detection systems to detect anomalous file access patterns. Conduct thorough audits of user permissions and remove unnecessary privileges to minimize the risk of exploitation. Additionally, implement file integrity monitoring to detect unauthorized changes to critical files. Organizations should also review logs for suspicious activity related to file downloads and path manipulation attempts. Educating users about the risks of credential compromise and enforcing strong authentication mechanisms (e.g., multi-factor authentication) will reduce the likelihood of attackers gaining the required authenticated access to exploit this vulnerability.

Description

CISA Thorium does not adequately validate the paths of downloaded files via 'download_ephemeral' and 'download_children'. A remote, authenticated attacker could access arbitrary files subject to file system permissions. Fixed in 1.1.2.

Impact

For European organizations using CISA Thorium 1.0.0, this vulnerability poses a risk of unauthorized file access by authenticated users, which could lead to exposure of sensitive configuration files, credentials, or intellectual property. Although the confidentiality impact is rated as none in the CVSS, in practical scenarios, access to arbitrary files can indirectly lead to confidentiality breaches if sensitive files are accessed. Integrity is impacted as attackers can potentially manipulate or read files that should be restricted, undermining trust in the system's data. This could affect sectors with strict data protection requirements such as finance, healthcare, and government agencies. The vulnerability could also facilitate lateral movement within networks if attackers gain access to critical files. Since the vulnerability requires authentication, the risk is higher in environments with weak access controls or where user accounts are shared or compromised. The medium severity suggests that while the threat is not critical, it should be addressed promptly to prevent escalation or exploitation in targeted attacks.

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #6OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks…
Implementation · Input Validation
Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174).
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V12.3.1 (opens in a new tab)
Attack patterns
Path Traversal (opens in a new tab)
Using Slashes and URL Encoding Combined to Bypass Validation Logic (opens in a new tab)
Manipulating Web Input to File System Calls (opens in a new tab)
Using Escaped Slashes in Alternate Encoding (opens in a new tab)
Using Slashes in Alternate Encoding (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 1 Oct 2025, 00:18 UTC

WeaknessesCWE-22

Technical details

References

Community reviews

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