CVE-2025-5963

TCC Bypass via Dylib Injection in Postbox

Published Jun 20, 2025 CVSS 4.0 · 4.8 Medium EPSS < 1% KEV · Not listed
Description
The Postbox's configuration on macOS, specifically the presence of entitlements: "com.apple.security.cs.allow-dyld-environment-variables" and "com.apple.security.cs.disable-library-validation" allows for Dynamic Library (Dylib) injection. A local attacker with unprivileged access can use environment variables like DYLD_INSERT_LIBRARIES to successfully inject code in application's context and bypass Transparency, Consent, and Control (TCC). Acquired resource access is limited to previously granted permissions by the user. Access to other resources beyond granted-permissions requires user interaction with a system prompt asking for permission.

The original company behind Postbox is no longer operational, the software will no longer receive updates. The acquiring company (em Client) did not cooperate in vulnerability disclosure.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2025-28697 The Postbox's configuration on macOS, specifically the presence of entitlements: "com.apple.security.cs.allow-dyld-environment-variables" and "com.apple.security.cs.disable-library-validation" allows for Dynamic Library (Dylib) injection. A local attacker with unprivileged access can use environment variables like DYLD_INSERT_LIBRARIES to successfully inject code in application's context and bypass Transparency, Consent, and Control (TCC). Acquired resource access is limited to previously granted permissions by the user. Access to other resources beyond granted-permissions requires user interaction with a system prompt asking for permission. The original company behind Postbox is no longer operational, the software will no longer receive updates. The acquiring company (em Client) did not cooperate in vulnerability disclosure.
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description The Postbox's configuration on macOS, specifically the presence of entitlements: "com.apple.security.cs.allow-dyld-environment-variables" and "com.apple.security.cs.disable-library-validation" allows for Dynamic Library (Dylib) injection. A local attacker with unprivileged access can use environment variables like DYLD_INSERT_LIBRARIES to successfully inject code in application's context and bypass Transparency, Consent, and Control (TCC). Acquired resource access is limited to previously granted permissions by the user. Access to other resources beyond granted-permissions requires user interaction with a system prompt asking for permission. The original company behind Postbox is no longer operational, the software will no longer receive updates. The acquiring company (em Client) did not cooperate in vulnerability disclosure.
Title TCC Bypass via Dylib Injection in Postbox
Weaknesses CWE-276
References
Metrics cvssV4_0

{'score': 4.8, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N'}

Subscriptions

No data.

Weaknesses

Sources

Status
PUBLISHED
Assigner
CERT-PL
Published
Updated
Jun 20, 2025, 1:14 PM
Reserved
Jun 10, 2025, 6:45 AM
Status
Deferred
Published
Jun 20, 2025, 10:15 AM
Modified
Jun 17, 2026, 9:49 AM