# CVE-2014-0777: OServer Out of Bounds Read

> Remote attackers can cause a denial of service in IOServer OPC Drivers via crafted Modbus packets, impacting industrial control systems.

- **Severity:** High 8.3 (`AV:N/AC:M/Au:N/C:P/I:P/A:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 Apr 2014
- **Updated:** 24 Sep 2025
- **Also known as:** GHSA-p75m-894q-gmxh

## What is CVE-2014-0777?

CVE-2014-0777 is a high-severity denial of service vulnerability in IOServer OPC Drivers, published on 11 Apr 2014. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Modbus slave/outstation driver in the OPC Drivers 1.0.20 and earlier in IOServer OPC Server allows remote attackers to cause a denial of service (out-of-bounds read and daemon crash) via a crafted packet.

Weakness: CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer), CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2014-0777?

It affects 2 products.


Products: Ioserver Ioserver Opc Server, Ioserver Opc Drivers.

## How do I fix CVE-2014-0777?

No fix has been published for CVE-2014-0777 yet. Limit exposure of the affected software until one is available.

## Is CVE-2014-0777 being exploited?

There is no known exploitation of CVE-2014-0777 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2014-0777 and fix it if it is affected.

What it is: CVE-2014-0777 is a high-severity denial of service vulnerability in IOServer OPC Drivers, published on 11 Apr 2014. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2014-0777 in the wild and no public exploit code.

Affected product: IOServer OPC Drivers. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2014-0777/ (Markdown: https://insights.sbomify.com/CVE-2014-0777/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2014-0777
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2014-0777
- OSV: https://osv.dev/vulnerability/CVE-2014-0777

---
From sbomify Insights: https://insights.sbomify.com/CVE-2014-0777/
Summaries are generated and may contain mistakes; the official description above is the record.