CVE-2015-2419 is a memory corruption vulnerability in Microsoft Internet Explorer. CISA added it to the Known Exploited Vulnerabilities catalogue on 28 March 2022, which means attackers have used it in real attacks. JScript in Microsoft Internet Explorer allows remote attackers to execute remote code or cause a denial of service (memory corruption) via a crafted web site.
What Memory Corruption Means in a Browser Exploit
Memory corruption is dangerous because it can let attacker-controlled content disturb how the browser parses, stores, or executes data, turning a normal web visit into a path to code execution or a crash. In an Internet Explorer context, that matters because the browser sits directly on the user’s trust boundary and can be reached through a crafted website.
For defenders, the key point is not the label alone but the consequence: a browser memory flaw can be triggered remotely, at scale, and without any local user action beyond visiting the page. That makes it a high-value delivery mechanism for drive-by exploitation and exploit chains.
Why Internet Explorer Memory Corruption Is Security-Relevant
Browser memory corruption is especially serious when the vulnerable component is script processing, because script engines can be reached by content that looks ordinary to a user. The primary danger is that a malformed page can steer execution flow, corrupt objects, or destabilize the process in a way that attackers can convert into remote code execution.
Because Internet Explorer has historically been embedded in enterprise workflows and legacy web applications, exposure can persist even after organisations reduce general browser use. A legacy browser vulnerability therefore remains relevant wherever the software is still present on endpoints, virtual desktops, or compatibility hosts.
For broader vulnerability context, teams should cross-check product exposure and exploit status against NIST National Vulnerability Database and the official CVE Program record, then use vendor guidance for version-specific remediation details.
Exposure Checks and Remediation Priorities
The first question is whether the vulnerable browser is still installed, enabled, or reachable on any asset that users can access. That means checking endpoint inventory, gold images, virtual desktop pools, kiosk systems, and any environment where legacy compatibility settings may keep Internet Explorer available.
If patching or removal cannot happen immediately, organisations should reduce exposure by limiting use of the browser, tightening web filtering, and constraining the systems that can reach untrusted sites. Legacy browser components deserve the same urgency as other remotely exploitable client-side flaws because exposure often depends on a small number of overlooked machines.
Vulnerability prioritisation should be driven by asset visibility and known exploitation, not by whether users believe they “do not use” the browser. A practical starting point is a disciplined vulnerability management guide approach that ties inventory, prioritisation, exceptions, and verification together.
Detection, Triage, and Post-Exploit Review
When a browser memory corruption issue is known to be exploited, detection should focus on evidence of unusual child processes, unexpected script-driven execution, suspicious downloads, and any process crash patterns that line up with attempted exploitation. A crash alone is not proof of compromise, but it is a useful signal when paired with suspicious browsing activity.
After patching or disabling the vulnerable component, teams should review whether the incident was only a failed exploit attempt or whether code execution already occurred. That review should include browser history, endpoint telemetry, downloaded payloads, and any follow-on activity that suggests the attacker used the browser as an initial access path.
Where browser exploitation is part of a wider intrusion pattern, the post-incident question is usually what the attacker did next, not just whether the browser flaw was fixed. That is why exploit visibility and rapid triage matter as much as the patch itself.
Risk and Threat Considerations
Browser memory corruption vulnerabilities are attractive because they can combine reach, reliability, and user familiarity into a single attack path. A crafted website can become the delivery mechanism for remote code execution or denial of service, which makes the flaw useful for drive-by compromise and for chaining into broader intrusion activity.
Failure mechanism: The attacker triggers malformed browser behavior that corrupts memory in the rendering or script engine, then uses that corruption to control execution or crash the process.
Impact: Successful exploitation can lead to remote code execution on the endpoint, followed by malware installation, credential theft, lateral movement, or service disruption if the browser crash is the only outcome.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
MITRE ATT&CK addresses the attack and risk surface, while NIST SP 800-53 Rev 5 and CIS Controls v8 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST SP 800-53 Rev 5 | SI-2 — Flaw Remediation | This CVE requires rapid flaw remediation and exception handling after confirmed exploitation. |
| SI-4 — System Monitoring | Exploit attempts and post-exploit activity require endpoint and process monitoring. | |
| Recommendation — Prioritise patching or compensating controls for exposed browsers and verify remediation completion. Monitor browser crashes, suspicious child processes, and follow-on execution after exploit activity. | ||
| CIS Controls v8 | CIS-7 — Continuous Vulnerability Management | The term is an actively exploited CVE, so continuous identification and remediation are central. |
| Recommendation — Track exposure to the browser flaw, prioritise affected assets, and validate closure. | ||
| MITRE ATT&CK | T1203 — Exploitation for Client Execution | A crafted website can deliver code execution through browser exploitation. |
| T1059 — Command and Scripting Interpreter | JScript exploitation can transition into script-based execution on the endpoint. | |
| Recommendation — Map suspicious web-delivered exploitation to T1203 and hunt for client-side execution. Investigate whether script execution followed the browser exploit and scope the resulting activity. | ||
Practitioner Guidance
Why practitioners should care: This kind of vulnerability is often more dangerous than its browser label suggests because the browser is a high-frequency trust boundary and a common entry point for initial access. Treat any confirmed exploitation as an endpoint security event, not just an application bug.
Practitioner takeaway: Prioritise removal or hardening of legacy browser exposure, then verify whether any affected endpoint shows signs of execution beyond the initial crash or page load.
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Reviewed and updated by the NHIMG editorial team on October 17, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org