# CVE-2013-4852: Integer overflow in n/a

> Remote SSH servers can trigger a heap-based buffer overflow via a negative size value in an RSA key signature, causing crashes or arbitrary code execution in PuTTY-based clients.

- **Severity:** Medium 6.8 (`AV:N/AC:M/Au:N/C:P/I:P/A:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 19 Aug 2013
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2013-4852, GHSA-x52x-v8xm-9r9j, UBUNTU-CVE-2013-4852

## What is CVE-2013-4852?

CVE-2013-4852 is a medium-severity vulnerability in Debian Debian Linux, published on 19 Aug 2013. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Integer overflow in PuTTY 0.62 and earlier, WinSCP before 5.1.6, and other products that use PuTTY allows remote SSH servers to cause a denial of service (crash) and possibly execute arbitrary code in certain applications that use PuTTY via a negative size value in an RSA key signature during the SSH handshake, which triggers a heap-based buffer overflow.

Weakness: CWE-189

## Which versions are affected by CVE-2013-4852?

It affects 5 products.


Products: Debian Debian Linux, Opensuse Opensuse, Putty Putty, Simon Tatham Putty, Winscp Winscp.

## How do I fix CVE-2013-4852?

Upgrade to a fixed version.

## Is CVE-2013-4852 being exploited?

There is no known exploitation of CVE-2013-4852 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2013-4852 and fix it if it is affected.

What it is: CVE-2013-4852 is a medium-severity vulnerability in Debian Debian Linux, published on 19 Aug 2013. 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-2013-4852 in the wild and no public exploit code.

Affected product: Debian Debian Linux. 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-2013-4852/ (Markdown: https://insights.sbomify.com/CVE-2013-4852/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2013-4852
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2013-4852
- OSV: https://osv.dev/vulnerability/CVE-2013-4852

---
From sbomify Insights: https://insights.sbomify.com/CVE-2013-4852/
Summaries are generated and may contain mistakes; the official description above is the record.