+O-OM-B Stream B: System Decommissioning / Legacy Management
---+O-OM-1-B Identify unused applications
---+O-OM-2-B Formalize decommissioning process
---+O-OM-3-B Review application lifecycle state regularly

O-OM-B Stream B: System Decommissioning / Legacy Management

From the perspective of the organization as a consumer of resources, the activities in this stream focus on the identification, management, and tracking of systems, applications, application dependencies, and services that are no longer used, have reached end of life, or are no longer actively developed or supported. Removal of unused systems and services improves manageability of the environment and reduces the organization's attack surface, while affording direct and indirect cost savings (e.g., reduced license count, reduced logging volume, or reduced analyst effort).

1. Forbhreathnú

O-OM-1-B Identify unused applications

Maturity level 1 objective of the practice: Foundational Practices

Benefit: Identification of unused software assets or components

Short description: Decommission unused applications and services as identified. Manage customer upgrades/migrations individually.

Identify unused applications on an _ad hoc_ basis, either by chance observation, or by occasionally performing a review. When you identify unused applications, process those findings for further action. If you have established a formal process for decommissioning unused applications, ensure teams are aware of and use it.

Manage customer/user migration from older versions of your products for each product and customer/user group. When a product version is no longer in use by any customer/user group, discontinue support for that version. However, at this level of maturity you may have a large number of product versions in active use across the customer/user base, requiring significant developer effort to back-port product fixes.

O-OM-2-B Formalize decommissioning process

Maturity level 2 objective of the practice: Managed, Responsive Processes

Benefit: Standardized decommissioning process decreasing the risk of forgetting components

Short description: Develop repeatable decommissioning processes for unused systems/services, and for migration from legacy dependencies. Manage legacy migration roadmaps for customers.

As part of decommissioning a system, application, or service, follow an established process for removing all relevant accounts, firewall rules, data, etc. from the operational environment. By removing these unused elements from configuration files, you improve the maintainability of infrastructure-as-code resources.

Follow a consistent process for timely replacement or upgrade of third-party applications, or application dependencies (e.g., operating system, utility applications, libraries), that have reached end of life.

Engage with customers and user groups for your products at or approaching end of life, to migrate them to supported versions in a timely manner.

O-OM-3-B Review application lifecycle state regularly

Maturity level 3 objective of the practice: Active Monitoring and Response

Benefit: Full visibility into lifecycle of all software assets

Short description: Proactively manage migration roadmaps, for both unsupported end-of-life dependencies, and legacy versions of delivered software.

Regularly evaluate the lifecycle state and support status of every software asset and underlying infrastructure component, and estimate their end-of-life. Follow a well-defined process for actively mitigating security risks arising as assets/components approach their end-of-life. Regularly review and update your process, to reflect lessons learned.

Establish a product support plan, providing clear timelines for ending support on older product versions. Limit product versions in active use to only a small number (e.g., N.x.x and N-1.x.x only). Establish and publicize timelines for discontinuing support on prior versions, and proactively engage with customers and user groups to prevent disruption of service or support.

1.1 Tagairtí

1.2 Ceanglais aitheanta

1.3 Rialacháin ghaolmhara

2. Ceanglais aitheanta

Ceanglais
Foinse	Ceanglas

3. Rialacháin ghaolmhara

Rialacháin
Foinse	Rialáil

OWASP -
EN: Publications of the OWASP Foundation, https://owasp.org/. OWASP® is a registered trademark of the OWASP Foundation, Inc.; GRCA is not affiliated with, nor endorsed by, the OWASP Foundation. Only the versions published by OWASP are authoritative.
- OWASP Application Security Verification Standard (ASVS) 5.0.0, May 2025, from OWASP/ASVS: © 2008-2025 The OWASP Foundation, licensed under CC BY-SA 4.0. Changes: divided into sections and converted into the GRCA format, the wording unchanged. These adaptations are shared under CC BY-SA 4.0 as well.
- OWASP Mobile Application Security Verification Standard (MASVS) v2.1.0, January 2024, from OWASP/masvs: © The OWASP Foundation, licensed under CC BY-SA 4.0. Changes: converted into the GRCA format, the wording unchanged. These adaptations are shared under CC BY-SA 4.0 as well.
- OWASP Mobile Application Security Weakness Enumeration (MASWE) v1.0.0, August 2026, from OWASP/maswe: © The OWASP Foundation, licensed under CC BY-SA 4.0. Changes: converted into the GRCA format, the wording unchanged, linked to the MASVS controls they map to. These adaptations are shared under CC BY-SA 4.0 as well.
- OWASP Mobile Application Security Testing Guide (MASTG) v2.0.0, June 2026, from OWASP/mastg: © The OWASP Foundation, licensed under CC BY-SA 4.0. The tests and best practices only, without code samples, images, tools or apps. Changes: converted into the GRCA format, the wording unchanged; references to other pages of the MASTG as links to mas.owasp.org; the weakness of each test in the numbering of MASWE v1 and linked to it. These adaptations are shared under CC BY-SA 4.0 as well.
- OWASP Software Assurance Maturity Model (SAMM) v2.2.0, July 2026, from owaspsamm/core: © The OWASP Foundation, licensed under CC BY-SA 4.0. Changes: converted into the GRCA format, the wording unchanged; short codes (G-SM-1-A) built from the model, the assessment questions as assessment procedures of their activities. These adaptations are shared under CC BY-SA 4.0 as well.
- OWASP Top 10:2025, from OWASP/Top10: © 2003-2025 The OWASP® Foundation, Inc., licensed under CC BY-SA 4.0. The ten categories, without the icons. Changes: converted into the GRCA format, the wording unchanged. These adaptations are shared under CC BY-SA 4.0 as well. The names of the mapped CWEs (Common Weakness Enumeration): © 2006–2026 The MITRE Corporation. License: The MITRE Corporation hereby grants you a non-exclusive, royalty-free license to use CWE for research, development, and commercial purposes. Any copy you make for such purposes is authorized on the condition that you reproduce MITRE’s copyright designation and this license in any such copy. See the CWE Terms of Use. CWE™ is a trademark of The MITRE Corporation.
DE: Veröffentlichungen der OWASP Foundation, https://owasp.org/. OWASP® ist eine eingetragene Marke der OWASP Foundation, Inc.; GRCA steht in keiner Verbindung zur OWASP Foundation und wird von ihr nicht unterstützt. Maßgeblich sind allein die von OWASP veröffentlichten Fassungen.
- OWASP Application Security Verification Standard (ASVS) 5.0.0, Mai 2025, aus OWASP/ASVS: © 2008-2025 The OWASP Foundation, lizenziert unter CC BY-SA 4.0. Änderungen: in Abschnitte aufgeteilt und in das GRCA-Format umgewandelt, der Wortlaut unverändert. Diese Bearbeitungen stehen ebenfalls unter CC BY-SA 4.0.
- OWASP Mobile Application Security Verification Standard (MASVS) v2.1.0, Januar 2024, aus OWASP/masvs: © The OWASP Foundation, lizenziert unter CC BY-SA 4.0. Änderungen: in das GRCA-Format umgewandelt, der Wortlaut unverändert. Diese Bearbeitungen stehen ebenfalls unter CC BY-SA 4.0.
- OWASP Mobile Application Security Weakness Enumeration (MASWE) v1.0.0, August 2026, aus OWASP/maswe: © The OWASP Foundation, lizenziert unter CC BY-SA 4.0. Änderungen: in das GRCA-Format umgewandelt, der Wortlaut unverändert, mit den MASVS-Controls verknüpft, denen sie zugeordnet sind. Diese Bearbeitungen stehen ebenfalls unter CC BY-SA 4.0.
- OWASP Mobile Application Security Testing Guide (MASTG) v2.0.0, Juni 2026, aus OWASP/mastg: © The OWASP Foundation, lizenziert unter CC BY-SA 4.0. Nur die Tests und Best Practices, ohne Codebeispiele, Bilder, Werkzeuge und Apps. Änderungen: in das GRCA-Format umgewandelt, der Wortlaut unverändert; Verweise auf andere Seiten des MASTG als Links zu mas.owasp.org; die Schwachstelle jedes Tests in der Nummerierung der MASWE v1 und mit ihr verknüpft. Diese Bearbeitungen stehen ebenfalls unter CC BY-SA 4.0.
- OWASP Software Assurance Maturity Model (SAMM) v2.2.0, Juli 2026, aus owaspsamm/core: © The OWASP Foundation, lizenziert unter CC BY-SA 4.0. Änderungen: in das GRCA-Format umgewandelt, der Wortlaut unverändert; Kürzel (G-SM-1-A) aus dem Modell gebildet, die Assessment-Fragen als Prüfverfahren ihrer Aktivitäten. Diese Bearbeitungen stehen ebenfalls unter CC BY-SA 4.0.
- OWASP Top 10:2025, aus OWASP/Top10: © 2003-2025 The OWASP® Foundation, Inc., lizenziert unter CC BY-SA 4.0. Die zehn Kategorien, ohne die Symbole. Änderungen: in das GRCA-Format umgewandelt, der Wortlaut unverändert. Diese Bearbeitungen stehen ebenfalls unter CC BY-SA 4.0. Die Namen der zugeordneten CWEs (Common Weakness Enumeration): © 2006–2026 The MITRE Corporation. MITRE erlaubt die Nutzung für Forschung, Entwicklung und kommerzielle Zwecke, wenn jede Kopie den Urheberrechtsvermerk und die Lizenz enthält; maßgeblich ist der englische Wortlaut der Lizenz oben und die CWE Terms of Use. CWE™ ist eine Marke der MITRE Corporation.