CVE-2025-59044VulnerabilityPublished 9 Sep 2025

CVE-2025-59044: himmelblau · Insecure Default Initialization of Resource

Affects himmelblauSource CVE Database V5

Not known to be exploited · CVSS 4.4 Medium · fixed in 0.9.23 : update himmelblau when convenient.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

4.4Medium

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 0.9.23

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

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

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

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
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: 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: 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 9 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 2026-10-25.

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

AI-suggested

1. Immediate upgrade of all himmelblau installations to version 0.9.23 or later (preferably 1.0.0 or above) to ensure the group-to-GID mapping uses unique Entra ID object IDs, eliminating collisions. 2. Until patching is complete, enforce tenant policy hardening to restrict arbitrary group creation in Microsoft Entra ID, limiting the ability of users to create groups with potentially colliding display names. 3. Audit existing group display names in Entra ID to identify and rename or consolidate duplicate group names to reduce collision risk. 4. Review and tighten Linux file system permissions and access control policies to minimize reliance solely on numeric GIDs for critical resources; consider supplementary access controls such as Access Control Lists (ACLs) or SELinux/AppArmor policies. 5. Monitor logs on himmelblau-joined hosts for unusual access patterns or unexpected group membership changes that could indicate exploitation attempts. 6. Educate administrators and users about the risks of creating groups with duplicate display names and enforce naming conventions to avoid collisions. 7. Implement least privilege principles for local accounts to reduce the risk that a low-privilege user can exploit this vulnerability. 8. Coordinate with Microsoft Entra ID administrators to review tenant policies and group management practices to align with security best practices.

Description

Himmelblau is an interoperability suite for Microsoft Azure Entra ID and Intune. Himmelblau 0.9.x derives numeric GIDs for Entra ID groups from the group display name when himmelblau.conf `id_attr_map = name` (the default configuration). Because Microsoft Entra ID allows multiple groups with the same `displayName` (including end-user–created personal/O365 groups, depending on tenant policy), distinct directory groups can collapse to the same numeric GID on Linux. This issue only applies to Himmelblau versions 0.9.0 through 0.9.22. Any resource or service on a Himmelblau-joined host that enforces authorization by numeric GID (files/dirs, etc.) can be unintentionally accessible to a user who creates or joins a different Entra/O365 group that happens to share the same `displayName` as a privileged security group. Users should upgrade to 0.9.23, or 1.0.0 or later, to receive a patch. Group to GID mapping now uses Entra ID object IDs (GUIDs) and does not collide on same-name groups. As a workaround, use tenant policy hardening to restrict arbitrary group creation until all hosts are patched.

Impact

For European organizations leveraging himmelblau to integrate Azure Entra ID with Linux systems, this vulnerability poses a risk of unauthorized access to sensitive files and services. Since access control on Linux often relies on numeric GIDs, the collision caused by identical group display names can allow users who are members of a benign or low-privilege group to gain access to resources intended for privileged groups. This can lead to data leakage, privilege escalation, and potential lateral movement within the network. Organizations with strict compliance requirements (e.g., GDPR) may face regulatory risks if sensitive personal or corporate data is exposed due to this flaw. The impact is particularly significant in environments with many user-created groups or where tenant policies allow broad group creation, increasing the likelihood of GID collisions. Additionally, since the vulnerability requires local privileges, attackers who have already compromised a low-privilege account could escalate their access. The lack of user interaction needed for exploitation increases the risk in multi-user or shared environments. Given the integration with Microsoft Entra ID and Intune, this vulnerability could affect hybrid cloud environments common in European enterprises, potentially undermining trust in identity and access management controls.

CWE-1188Initialization of a Resource with an Insecure Default (opens in a new tab)
Base weakness
The product initializes or sets a resource with a default that is intended to be changed by the product's installer, administrator, or maintainer, but the default is not secure.
OWASP Cheat Sheets
Forgot Password (opens in a new tab)
OWASP ASVS 4.0.3
V2.3.1 (opens in a new tab)
V2.6.2 (opens in a new tab)
V2.7.6 (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

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 17 Sep 2025, 00:59 UTC

WeaknessesCWE-1188

Technical details

References

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