CVE-2009-4178: HP OpenView NNM OvWebHelp.exe heap buffer overflow via Topic parameter

Automated analysis

Generated by VULONE's analysis model from the NVD record, CISA KEV and EPSS data on 18 September 2026. Confidence: medium.

high priorityCVSS 2.0 base score of 10 with network, unauthenticated, low-complexity code execution and very high EPSS, though it is not in KEV and the product is legacy.

What it is

OvWebHelp.exe in HP OpenView Network Node Manager 7.01, 7.51 and 7.53 contains a heap-based buffer overflow reachable through a long Topic parameter. A remote, unauthenticated attacker can trigger it and execute arbitrary code on the NNM host, which is a high-value management system. The record does not state whether a public exploit exists beyond the referenced advisories.

Impact

Successful exploitation gives the attacker arbitrary code execution in the context of the OvWebHelp.exe process, typically leading to full compromise of the NNM server. From there an attacker could pivot into the monitored network infrastructure.

Attack surface

The flaw is network-reachable (AV:N) with no authentication (Au:N) and low complexity (AC:L) per the CVSS 2.0 vector. It is triggered by supplying an oversized Topic parameter to OvWebHelp.exe; no user interaction is indicated.

Exploitation

Not listed in CISA KEV and no ransomware association is recorded, but EPSS is very high (0.74024, 99.459th percentile), indicating substantial predicted exploitation activity. Reference tags include Patch and Vendor Advisory, and no public exploit tag is present in the record.

What to do

• Apply the HP vendor patch referenced in the HP support document and TippingPoint advisory TPTI-09-11.
• Restrict network access to the NNM web/help components (OvWebHelp.exe) to trusted management hosts only.
• If the affected NNM versions cannot be patched promptly, isolate or retire them, as 7.01/7.51/7.53 are long end-of-life.
• Monitor and filter requests containing abnormally long Topic parameters at the web tier or WAF.
• Verify no unauthorized listeners or processes are exposed on the NNM host after remediation.

Detection

• Inspect web/proxy logs for requests to OvWebHelp.exe with unusually long or malformed Topic parameters.
• Monitor for crashes or restarts of OvWebHelp.exe and related NNM processes, which may indicate exploitation attempts.
• Alert on unexpected child processes or outbound connections originating from the NNM server.
• Correlate IDS/IPS signatures for HP OpenView NNM buffer overflow attempts against host logs.

This assessment is produced automatically and is not human-reviewed. Verify against the vendor advisory before acting on it.