Raw vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:NSummary
CVE-2025-15576 is a high-severity Improper Privilege Management (CWE-269) vulnerability in Freebsd Freebsd. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Abuse Elevation Control Mechanism (T1548); ranked at the 2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to AC-2 (Account Management) and AC-24 (Access Control Decisions) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2025-15576 is a jail isolation bypass vulnerability in the FreeBSD kernel's jail subsystem. It affects configurations where two sibling jails are restricted to separate filesystem trees—meaning neither jail root directory is an ancestor of the other—but a shared directory is accessible via a nullfs mount. In such setups, jailed processes can exchange directory file descriptors over a unix domain socket connection. During filesystem name lookups, the kernel fails to properly validate if a descriptor-referenced directory descends below the current process's jail root, enabling access to paths outside the jail's chroot boundary.
Exploitation requires local access (AV:L) with low privileges (PR:L) and high attack complexity (AC:H), typically involving cooperating processes across the two sibling jails to establish a unix domain socket and pass directory descriptors. Successful exploitation grants the jailed process full filesystem access, resulting in high confidentiality (C:H) and integrity (I:H) impacts with changed scope (S:C) but no availability impact (A:N), as scored at CVSS 7.5 (CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N). The vulnerability is linked to CWE-269 (Privilege Context Switching Error), CWE-488 (Exposure of Data Element to Wrong Session), and CWE-790 (Incomplete Filtering of File Descriptors).
The FreeBSD Security Advisory at https://security.freebsd.org/advisories/FreeBSD-SA-26:04.jail.asc details the issue and provides patches. Even with patches applied, administrators must ensure unprivileged users on the jail host cannot pass directory descriptors to jailed processes.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-208409
Vulnerability Data
If two sibling jails are restricted to separate filesystem trees, which is to say that neither of the two jail root directories is an ancestor of the other, jailed processes may nonetheless be able to access a shared directory via…
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a nullfs mount, if the administrator has configured one. In this case, cooperating processes in the two jails may establish a connection using a unix domain socket and exchange directory descriptors with each other. When performing a filesystem name lookup, at each step of the lookup, the kernel checks whether the lookup would descend below the jail root of the current process. If the jail root directory is not encountered, the lookup continues. In a configuration where processes in two different jails are able to exchange file descriptors using a unix domain socket, it is possible for a jailed process to receive a directory for a descriptor that is below that process' jail root. This enables full filesystem access for a jailed process, breaking the chroot. Note that the system administrator is still responsible for ensuring that an unprivileged user on the jail host is not able to pass directory descriptors to a jailed process, even in a patched kernel.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 5 hardening rules · 5 OS baselines
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Mitigating Controls (NIST 800-53 r5) AI
Account management directly governs assignment and tracking of privileges so proper implementation stops the weakness from being introduced.
Requiring explicit access-control decisions ensures privileges are evaluated rather than assumed or omitted.
Access enforcement applies the correct privilege checks at every request, structurally preventing unintended spheres of control.
AC-4 controls information flows between entities, reducing cross-session leakage.
Separation of duties constrains how privileges may be assigned, reducing the chance of overly broad actor control.
Least privilege is the direct countermeasure to improper privilege management; implementing it eliminates the root cause.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
PR.AA-05 enforces least privilege/SoD and periodic reviews that directly remove most privilege-assignment defects, yet CWE-269 also covers escalation paths and role design outside a single access-management control.
Secure SDLC practices directly require proper sanitization and filtering of special elements before data passes downstream.
Identifying recorded vulnerabilities can surface missing input filters during code or configuration review.
PR.AA-01 supplies credential/identity lifecycle support that can reduce some privilege-assignment errors but does not itself assign, modify, or check privileges, leaving most of CWE-269's risk unaddressed.
Protecting data-in-use directly addresses runtime leakage of session data to unauthorized contexts.
Logical access controls and segmentation can be applied to isolate session state within applications or environments.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Requiring owner approval, segregation of duties, and periodic reviews prevents the assignment of excessive or unnecessary privileges to users or processes.
Enforcing minimum-necessary privileges, temporary grants, and separation of administrative versus normal identities prevents the over-assignment of rights that CWE-269 describes.
Security testing can detect the weakness but does not itself implement the preventive control.
Dynamic techniques that grant the minimum necessary rights for a given time window and revoke them afterward reduce the window in which excessive or unnecessary privileges can be exploited.
Explicit restrictions on privileged access and segregation of duties limit the scope of privileges that can be assigned, reducing the chance that excessive or unnecessary privileges are granted to entities.
Defining and communicating authorization levels for each role limits the assignment of excessive or unnecessary privileges.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Windows 10 (1 rule)
- V-220712 Only accounts responsible for the administration of a system must have Administrator rights on the system. prevents CWE-269
Windows 11 (1 rule)
- V-253269 Only accounts responsible for the administration of a system must have Administrator rights on the system. prevents CWE-269
Windows Server 2016 (1 rule)
- V-225007 Only administrators responsible for the member server or standalone or nondomain-joined system must have Administrator rights on the system. prevents CWE-269
Windows Server 2019 (1 rule)
- V-205746 Windows Server 2019 must only allow Administrators responsible for the member server or standalone or nondomain-joined system to have Administrator rights on the system. prevents CWE-269
Windows Server 2022 (1 rule)
- V-254428 Windows Server 2022 must only allow administrators responsible for the member server or standalone or nondomain-joined system to have Administrator rights on the system. prevents CWE-269