Is CVE-2015-3113 (Adobe Flash Player Heap-Based Buffer Overflow) being exploited in the wild?

Yes. CISA added CVE-2015-3113 to its Known Exploited Vulnerabilities catalogue on 13 April 2022, which it does only when there is reliable evidence of active exploitation. CISA has not linked it to known ransomware campaigns. Heap-based buffer overflow vulnerability in Adobe Flash Player allows remote attackers to execute code. Any organisation running the affected product should treat remediation as urgent.

What “being exploited in the wild” means for this CVE

For a vulnerability like CVE-2015-3113, “exploited in the wild” means the issue has moved beyond proof-of-concept and is being used against real systems. The practical question is not whether the flaw exists, but whether exposed instances still have a meaningful chance of compromise and whether you should treat it as an active incident response and remediation priority.

That changes the response posture. Once a flaw is confirmed in CISA’s Known Exploited Vulnerabilities catalogue, it should be handled as an exploitation problem, not only a patch-management item. The relevant decision is whether any asset still exposes the vulnerable Adobe Flash Player component and whether compensating controls are strong enough to reduce the attack surface until it is removed or disabled.

How to confirm exposure and reduce attack surface

Start by identifying where Adobe Flash Player is installed or still enabled, including older desktops, virtual desktops, kiosk systems, legacy browser profiles and any environment that has been left behind after a larger migration. The most important practical check is whether the vulnerable component is reachable in day-to-day user workflows, because dormant software that can still be launched is often enough for exploitation.

If the product is still present, remove or disable it according to vendor guidance and verify that it is no longer callable from browsers or embedded application paths. For a vulnerability already confirmed as actively exploited, delay is the enemy: exposure often persists because organisations remember that Flash is “deprecated” while overlooking long-lived systems, offline images, packaged applications and user-installed copies.

When you need a structured triage path for actively exploited issues, use the Zero-Day and Exploited Vulnerabilities Guide to align urgency, emergency mitigation and post-patch verification. For broader prioritisation and remediation workflow, the Vulnerability Management Guide is the better operating model than ad hoc ticketing.

What to do if patching or removal is delayed

If immediate removal is not possible, reduce exposure in layers. The objective is to make exploitation harder, more visible and less useful to an attacker while you work the remediation queue. That usually means restricting which hosts can reach the vulnerable software, tightening browser and plugin execution paths, and limiting user populations that can trigger the code path at all.

Where the vulnerable software remains temporarily necessary, treat it as a constrained exception with explicit expiry, business owner sign-off and a plan to verify continued necessity. A compensating-control plan is only credible if you can show that the affected asset set is known, the exception has a short life, and the removal date is owned by a team that can actually execute it.

Use exposure analytics to keep the queue honest. If your program already tracks urgency with the Vulnerability Management Guide approach, then actively exploited items should rise above routine CVE backlog processing, because the question is whether the asset remains attackable right now, not whether it will be patched eventually.

Standards & Framework Alignment

This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.

NIST CSF 2.0, CIS Controls v8 and NIST SP 800-53 Rev 5 set the governance and control requirements practitioners need to meet.

Framework	Control / Reference	Relevance
NIST CSF 2.0	ID.RA-01 — Asset Vulnerability Identification	Actively exploited CVEs require identifying exposed assets and vulnerable software.
	PR.PS-03 — System Configuration	Removing or disabling vulnerable software is a configuration-hardening action.
Recommendation — Identify every asset still exposed to the vulnerable product and track it to remediation. Disable or remove the vulnerable component and verify the hardened state persists.
CIS Controls v8	CIS-7 — Continuous Vulnerability Management	Confirmed exploitation makes prioritised vulnerability handling essential.
Recommendation — Prioritise the CVE for urgent remediation and track closure against an exception deadline.
NIST SP 800-53 Rev 5	RA-5 — Vulnerability Monitoring and Scanning	The question is about confirming exposure to a known exploited vulnerability.
	SI-2 — Flaw Remediation	Actively exploited code flaws require rapid remediation or compensating mitigation.
Recommendation — Scan for remaining vulnerable instances and validate that exposed systems are eliminated. Apply the fix or compensating mitigation and confirm the flaw is no longer exploitable.

Practitioner Guidance

What to prioritise: Remove or disable the vulnerable Flash component first, then confirm there are no secondary execution paths such as bundled applications, archived builds or legacy browsers that still invoke it.

What to verify: Confirm both inventory and reachability. It is not enough to know the product existed in the environment; you need evidence that it cannot still be launched, loaded or re-enabled by users or software packaging.

Escalation / exception: If remediation must wait, treat the asset as an active risk exception with a short expiry, explicit owner and compensating controls that materially reduce access to the vulnerable code path.

Practitioner takeaway: For an exploited-in-the-wild CVE, the key question is not “do we have the patch?” but “can anything in the environment still be reached and abused before the fix is fully effective?”