# CVE-2006-1652: Memory corruption in n/a

> Buffer overflows in UltraVNC allow remote code execution via malicious servers or denial of service via long HTTP requests.

- **Severity:** Critical 9.0 (`AV:N/AC:L/Au:S/C:C/I:C/A:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 6 Apr 2006
- **Updated:** 7 Aug 2024
- **Also known as:** GHSA-m87x-468w-hp6j

## What is CVE-2006-1652?

CVE-2006-1652 is a critical memory corruption vulnerability in n/a, published on 6 Apr 2006. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Multiple buffer overflows in (a) UltraVNC (aka Ultr@VNC) 1.0.1 and earlier and (b) tabbed_viewer 1.29 (1) allow user-assisted remote attackers to execute arbitrary code via a malicious server that sends a long string to a client that connects on TCP port 5900, which triggers an overflow in Log::ReallyPrint; and (2) allow remote attackers to cause a denial of service (server crash) via a long HTTP GET request to TCP port 5800, which triggers an overflow in VNCLog::ReallyPrint.

Weakness: CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2006-1652?

It affects 2 products.


Products: Ultravnc Tabbed Viewer, Ultravnc Vnc Viewer.

## How do I fix CVE-2006-1652?

No fix has been published for CVE-2006-1652 yet. Limit exposure of the affected software until one is available.

## Is CVE-2006-1652 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2006-1652 exists.

Public exploit code:

- UltraVNC 1.0.1 - Multiple Remote Error Logging Buffer Overflow Vulnerabilities (1) (exploitdb)
- UltraVNC 1.0.1 - Multiple Remote Error Logging Buffer Overflow Vulnerabilities (2) (exploitdb)
- UltraVNC 1.0.1 Client Buffer Overflow (metasploit)
- UltraVNC 1.0.1 - Client Buffer Overflow (Metasploit) (exploitdb)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2006-1652 and fix it if it is affected.

What it is: CVE-2006-1652 is a critical memory corruption vulnerability in n/a, published on 6 Apr 2006. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2006-1652 exists.

Affected product: n/a. 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-2006-1652/ (Markdown: https://insights.sbomify.com/CVE-2006-1652/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2006-1652
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2006-1652
- OSV: https://osv.dev/vulnerability/CVE-2006-1652

---
From sbomify Insights: https://insights.sbomify.com/CVE-2006-1652/
Summaries are generated and may contain mistakes; the official description above is the record.