CVE-2025-64403VulnerabilityPublished 12 Nov 2025

CVE-2025-64403: Apache OpenOffice · Missing Authorization

Affects Apache OpenOfficeSource CVE Database V5

Not known to be exploited · CVSS 8.1 High · fixed in 4.1.16 : patch Apache OpenOffice soon.

Data as of 26 Oct 2026, 07:57 UTC

CVSS 3.1 base score

8.1High

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

EPSS: 1.2% chance of exploitation in 30 days – higher than 69% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 4.1.16

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
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: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
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 12 Nov 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
Apache Software Foundation Apache OpenOffice	Affected =0	Fixed in–

AI-suggested

To mitigate CVE-2025-64403, European organizations should immediately upgrade all Apache OpenOffice installations to version 4.1.16 or later, which contains the fix for the missing authorization issue. Until upgrades are completed, organizations should implement strict document handling policies, including disabling automatic loading of external data sources in Calc if configurable. User awareness training should emphasize the risks of opening spreadsheet documents from untrusted or unknown sources to reduce the likelihood of successful phishing attacks. Network-level controls such as blocking or monitoring outbound connections to untrusted external data sources referenced in documents can help detect or prevent exploitation attempts. Organizations should also audit and restrict the use of Apache OpenOffice in high-risk environments and consider alternative office suites with stronger security controls if feasible. Regular vulnerability scanning and patch management processes must be enforced to ensure timely application of security updates. Finally, monitoring for unusual network activity or data exfiltration attempts related to document processing can provide early detection of exploitation attempts.

Description

Apache OpenOffice Calc spreadsheet can contain links to other files, in the form of "external data sources". A missing Authorization vulnerability in Apache OpenOffice allowed an attacker to craft a document that would cause such links to be loaded without prompt. This issue affects Apache OpenOffice: through 4.1.15. Users are recommended to upgrade to version 4.1.16, which fixes the issue.

Impact

For European organizations, the impact of CVE-2025-64403 can be significant, especially in sectors that rely heavily on Apache OpenOffice for document creation and data analysis, such as government agencies, educational institutions, and public administration. The automatic loading of external data sources without user consent can lead to unauthorized disclosure of sensitive information, including internal network details or confidential data referenced in spreadsheets. Additionally, attackers could manipulate data integrity by injecting malicious external content, potentially affecting decision-making processes or financial calculations. Since the vulnerability requires user interaction (opening a malicious document), phishing or social engineering campaigns could be used to deliver the exploit. The widespread use of Apache OpenOffice in Europe, particularly in organizations favoring open-source solutions, increases the attack surface. Unpatched systems could face data breaches, loss of trust, and compliance violations under GDPR due to unauthorized data access. Although no active exploits are known, the high CVSS score and ease of exploitation warrant urgent mitigation to prevent future attacks.

CWE-862Missing Authorization (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #4OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
Architecture and Design
Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries.
Architecture and Design
Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.8 (opens in a new tab)
V13.4.2 (opens in a new tab)
V7.2.2 (opens in a new tab)
Attack patterns
Exploitation of Thunderbolt Protection Flaws (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 19 Nov 2025, 11:14 UTC

WeaknessesCWE-862

Technical details

References

Community reviews

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