VulnerabilityPublished 15 Dec 2025

CVE-2025-67809: Zimbra Collaboration Suite · CVE-2025-67809 is a medium severity

Source CVE Database V5

Not known to be exploited · CVSS 4.7 Medium.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score

4.7Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 21% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: High
Privileges Required: None
User Interaction: Required
Scope: Changed
Confidentiality: Low
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: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
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: 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: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to 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 15 Dec 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

AI-suggested

European organizations should immediately upgrade Zimbra Collaboration Suite to versions beyond 10.1 where the hardcoded Flickr API credentials have been removed and revoked. If upgrading is not immediately feasible, disabling the Flickr Zimlet integration is recommended to prevent exposure. User education is critical: train users to recognize and reject suspicious OAuth authorization requests, especially those that appear unexpectedly or from untrusted sources. Implement monitoring of OAuth token usage and Flickr API access logs to detect anomalous activity. Employ network controls to restrict access to Zimbra Zimlet resources if possible. Review and audit all third-party integrations for hardcoded credentials or insecure practices. Finally, ensure incident response plans include steps for OAuth-related compromises and data privacy breach notifications under GDPR.

Description

CVE-2025-67809 is a medium severity vulnerability in Zimbra Collaboration Suite (ZCS) versions 10.0 and 10.1 involving a hardcoded Flickr API key and secret embedded in the publicly accessible Flickr Zimlet. This exposure allows unauthorized parties to extract these credentials and misuse the Flickr integration by impersonating the legitimate application and initiating OAuth flows. If a user is tricked into approving such a request, the attacker could gain access to the user's Flickr data, impacting confidentiality and integrity. The vulnerability does not allow direct system compromise or availability disruption and requires user interaction and high attack complexity. The hardcoded credentials have been removed and revoked in later versions. European organizations using affected Zimbra versions with Flickr Zimlet enabled should update promptly and educate users about phishing risks related to OAuth approvals.

Impact

For European organizations, the primary impact lies in the potential unauthorized access to Flickr user data linked to corporate accounts or employees using the Flickr Zimlet. This could lead to exposure of sensitive images or metadata, potentially violating privacy regulations such as GDPR if personal data is involved. While the vulnerability does not compromise Zimbra servers directly, the misuse of OAuth tokens could undermine user trust and lead to reputational damage. Organizations relying on Zimbra Collaboration with Flickr integration may face increased phishing or social engineering risks as attackers attempt to trick users into approving malicious OAuth requests. The medium severity reflects limited direct system impact but notable confidentiality concerns. Availability and integrity of Zimbra services remain unaffected. The risk is heightened in environments where Flickr is actively used for business or employee collaboration.

CWE-798Use of Hard-coded Credentials (opens in a new tab)
Base weaknessLikelihood of exploit: HighOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
The product contains hard-coded credentials, such as a password or cryptographic key.
Architecture and Design
For outbound authentication: store passwords, keys, and other credentials outside of the code in a strongly-protected, encrypted configuration file or database that is protected from access by all outsiders, including other local users on the same system. Properly protect the key (CWE-320).
Architecture and Design
For inbound authentication: Rather than hard-code a default username and password, key, or other authentication credentials for first time logins, utilize a "first login" mode that requires the user to enter a unique strong password or key.
Architecture and Design
If the product must contain hard-coded credentials or they cannot be removed, perform access control checks and limit which entities can access the feature that requires the hard-coded credentials. For example, a feature might only be enabled through the system console instead of through a network connection.
OWASP Cheat Sheets
Key Management (opens in a new tab)
REST Security (opens in a new tab)
JSON Web Token for Java (opens in a new tab)
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V2.10.4 (opens in a new tab)
V6.4.1 (opens in a new tab)
V3.5.2 (opens in a new tab)
Attack patterns
Read Sensitive Constants Within an Executable (opens in a new tab)
Try Common or Default Usernames and Passwords (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

Description

AI analysisMachine-generated, updated 22 Dec 2025, 20:40 UTC

WeaknessesCWE-798

Technical details

References

Community reviews

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