CVE-2015-2425 is a memory corruption vulnerability in Microsoft Internet Explorer. CISA added it to the Known Exploited Vulnerabilities catalogue on 25 May 2022, which means attackers have used it in real attacks. Microsoft Internet Explorer contains a memory corruption vulnerability that allows remote attackers to execute code or cause denial-of-service (DoS).
Why this vulnerability matters in Internet Explorer
Memory corruption in a browser is dangerous because it can let crafted content break normal execution flow inside a widely used client-side application. In practical terms, that can turn a simple browsing action into remote code execution or a crash, which is why KEV-listed browser flaws deserve fast attention even when they are old.
For readers tracking exposure, the key question is whether any supported or legacy systems still rely on the affected browser component, whether those systems can still reach untrusted web content, and whether the organisation has a path to remove or isolate the software before exploitation occurs. The official CVE Program and the NIST National Vulnerability Database are the authoritative places to confirm record details and supporting references.
How exploitation typically works
Memory corruption bugs are usually abused by feeding a browser specially crafted web content that triggers unsafe handling of objects in memory. Once control data or pointers are corrupted, an attacker may be able to execute code in the context of the browser process, which makes the flaw useful for initial foothold, drive-by delivery, or follow-on payload staging.
The practical danger is not only the crash itself. A reliable browser exploit can be combined with phishing, malvertising, or a compromised website to reach victims without requiring them to open an attachment or install anything. That makes browser memory corruption a classic delivery mechanism for intrusion chains that begin with ordinary user activity.
What organisations should check
Exposure assessment starts with asset inventory. Organisations should identify whether Internet Explorer is still present anywhere in the environment, whether it is enabled for compatibility use, and whether any business process still depends on it. Systems that can browse the public internet, open HTML content, or render untrusted web pages have materially higher exposure than isolated kiosks or tightly controlled internal-only uses.
Vendor guidance and patch notes should be reviewed alongside the CISA KEV catalogue entry for this CVE, because KEV status means exploitation has already been observed. The most important decision is not academic confirmation of the bug, but whether any reachable system remains in a state where exploitation is still plausible.
Where exposure cannot be eliminated immediately, organisations should narrow the attack surface by restricting browser use, removing unnecessary access paths, and reducing the ability of users to open untrusted content in the vulnerable application. Those steps do not fix the flaw, but they can materially reduce the chance of successful exploitation while remediation is underway.
Remediation, detection, and post-exploitation review
Remediation should prioritise the vendor advisory and apply the relevant fixes as soon as they are available for the affected environment. If patching is delayed, compensating controls should focus on removing the vulnerable browser from routine use, limiting web access on affected hosts, and isolating systems that must remain online for compatibility reasons.
Detection should look for signs that a browser process crashed unexpectedly, spawned unusual child processes, or initiated suspicious follow-on activity after a web session. After patching, security teams should review for signs of compromise that may have occurred before the fix, because exploitation of a browser memory corruption issue can produce secondary payloads, persistence, or credential theft even if the original exploit is no longer available.
If exploitation is suspected, treat the affected endpoint as a potential initial access point and investigate adjacent accounts, browser sessions, downloaded files, and any unexpected outbound connections. That review helps determine whether the issue stopped at a crash or progressed into a broader intrusion.
Risk and Threat Considerations
Browser memory corruption is especially risky because it can be triggered remotely through content users already expect to trust, and because successful exploitation may lead directly to code execution on the endpoint. In a legacy browser like Internet Explorer, the risk is amplified when organisations still need the software for compatibility and cannot remove it quickly.
Failure mechanism: An attacker delivers crafted web content that corrupts process memory, then uses the corrupted state to redirect execution or destabilise the browser.
Impact: The result can be remote code execution, denial of service, or a compromise chain that reaches deeper into the endpoint than the browser itself.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
CIS Controls v8, NIST SP 800-53 Rev 5 and NIST CSF 2.0 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| CIS Controls v8 | CIS-7 — Continuous Vulnerability Management | This CVE requires asset visibility, prioritization, and remediation of known exploited software. |
| Recommendation — Prioritise Internet Explorer removal or patching under CIS-7 and verify exposure across the estate. | ||
| NIST SP 800-53 Rev 5 | SI-2 — Flaw Remediation | The page centres on remediating a known memory corruption flaw in browser software. |
| SI-3 — Malicious Code Protection | Browser exploitation is a common delivery path for malicious code and post-exploit payloads. | |
| RA-5 — Vulnerability Monitoring and Scanning | Exposure depends on finding systems that still run or expose the vulnerable browser component. | |
| Recommendation — Track, test, and apply the vendor fix for the affected browser under SI-2. Harden endpoint controls under SI-3 to reduce exploit delivery and follow-on payload execution. Use RA-5 to inventory hosts, confirm Internet Explorer presence, and validate remediation status. | ||
| NIST CSF 2.0 | DE.CM-09 — Malicious code is detected. | Successful exploitation may show up as malicious or unusual endpoint activity after web content is rendered. |
| Recommendation — Monitor endpoints for suspicious browser-driven execution and post-exploit behavior under DE.CM-09. | ||
Practitioner Guidance
Why practitioners should care: Treat this kind of browser flaw as a priority exposure issue, not just an application bug. If a legacy browser remains installed, the real control question is whether any host can still reach untrusted content through it.
What to watch for: Pay special attention to compatibility exceptions, unmanaged endpoints, and environments where remediation is deferred because “the browser still works.” Those are the places where old client-side vulnerabilities tend to survive longest.
Practitioner takeaway: Reduce the number of places where the vulnerable browser can still execute at all, then verify that no endpoint still depends on it as a normal user path.