CVE-2025-30354
Usebruno Bruno ≤ 1.39.1
Raw vector
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XSummary
CVE-2025-30354 is a high-severity Permissive Cross-domain Security Policy with Untrusted Domains (CWE-942) vulnerability in Usebruno Bruno. Its CVSS base score is 8.7 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Drive-by Compromise (T1189); ranked at the 29th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to AC-4 (Information Flow Enforcement) and SC-7 (Boundary Protection) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-9430
Vulnerability Data
Bruno is an open source IDE for exploring and testing APIs. A bug in the assertion runtime caused assert expressions to run in Developer Mode, even if Safe Mode was selected. The bug resulted in the sandbox settings to be…
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ignored for the particular case where a single request is run/sent. This vulnerability's attack surface is limited strictly to scenarios where users import collections from untrusted or malicious sources. The exploit requires deliberate action from the user—specifically, downloading and opening an externally provided malicious Bruno collection. The vulnerability is fixed in 1.39.1.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V3.4.3V3.4.6V3.5.2
Mitigating Controls (NIST 800-53 r5) AI
Information flow enforcement requires approved authorizations and would reject policies permitting untrusted domains.
Boundary protection at external interfaces stops unauthorized cross-domain communication allowed by permissive policies.
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.
Hardened configuration baselines and reviews directly prevent permissive CSP or cross-domain policies.
Secure SDLC activities include review and testing of web security policies to avoid untrusted domains.
Vulnerability identification processes can surface permissive policy misconfigurations.
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.
Security testing can detect overly permissive cross-domain policies but does not prevent their initial introduction.
Network security policies can restrict cross-domain communication but do not specifically mandate strict CSP or cross-domain policy configuration.
Security of network services includes defining allowed endpoints, which can limit untrusted domains but does not directly address web-client policy files.
Web filtering can block untrusted domains at the network level, partially mitigating permissive cross-domain policies.
Application security requirements should specify secure CSP and cross-domain policy settings, directly addressing the weakness.
Secure architecture principles include defining trust boundaries, which can reduce permissive cross-domain allowances.