CVE-2015-4049
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedUnisys Libra 43xx, 63xx, and 83xx, and FS600 class systems with MCP-FIRMWARE 40.0 before 40.0IC4 Build 270 might allow remote authenticated users to cause a denial of service (data corruption or system crash) via vectors related to using program operators during EPSILON (level 5) based codefiles at peak memory usage, which triggers CPM stack corruption.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceMemory corruption vulnerability in Unisys Libra 43xx/63xx/83xx and FS600 class mainframes running MCP-FIRMWARE versions prior to 40.0IC4 Build 270. Remote authenticated users can trigger CPM (Central Processing Module) stack corruption by using program operators during EPSILON (level 5) based codefile execution at peak memory usage, leading to data corruption or system crash.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data= 40.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- High
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify MCP-FIRMWARE versionRetrieve the firmware version from the Unisys mainframe system information. On the MCP system, use the system diagnostics or firmware management interface to display the current MCP-FIRMWARE build and version number.Affected if The installed version is 40.0 or any version prior to 40.0IC4 Build 270. Compare your version against this threshold.
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Verify program operator function availabilityCheck if program operator functions are enabled and accessible to authenticated users on the system. Review the user authentication and authorization configuration for MCP system operator privileges.Affected if Authenticated users have access to program operator functions, as this is required to trigger the vulnerability.
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Confirm EPSILON level 5 codefile execution capabilityDetermine whether EPSILON-based codefiles with privilege level 5 can be executed in the environment. Check the system configuration for EPSILON interpreter and codefile execution settings.Affected if EPSILON level 5 codefile execution is permitted, as this is the specific execution context needed for exploitation.
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Assess memory utilization patternsMonitor current system memory usage and determine if the system operates near or at peak memory capacity. Review memory allocation statistics for the Central Processing Module.Affected if The system experiences peak memory usage periods, as the vulnerability is triggered during high memory utilization.
The system is affected if it runs MCP-FIRMWARE version 40.0 or prior to 40.0IC4 Build 270 AND allows authenticated users to execute program operators during EPSILON level 5 codefile operations at peak memory usage.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUpgrade MCP-FIRMWARE to version 40.0IC4 Build 270 or later. If immediate patching is not possible, restrict authenticated user access to program operator functions during high memory utilization periods and monitor for anomalous system behavior.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA3.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2015-4049 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2015-4049 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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