# CVE-2005-0039: Weak cryptography in n/a

> Remote attackers can decrypt IPsec communications by modifying outer packets when specific configurations are used, exposing sensitive data.

- **Severity:** Medium 6.4 (`AV:N/AC:L/Au:N/C:P/I:P/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 10 May 2005
- **Updated:** 7 Aug 2024
- **Also known as:** GHSA-8wqc-vgv5-hpgj

## What is CVE-2005-0039?

CVE-2005-0039 is a medium-severity vulnerability in n/a, published on 10 May 2005. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Certain configurations of IPsec, when using Encapsulating Security Payload (ESP) in tunnel mode, integrity protection at a higher layer, or Authentication Header (AH), allow remote attackers to decrypt IPSec communications by modifying the outer packet in ways that cause plaintext data from the inner packet to be returned in ICMP messages, as demonstrated using bit-flipping attacks and (1) Destination Address Rewriting, (2) a modified header length that causes portions of the packet to be interpreted as IP Options, or (3) a modified protocol field and source address.

## Which versions are affected by CVE-2005-0039?

It affects 1 product.


Products: Nissc Ipsec.

## How do I fix CVE-2005-0039?

No fix has been published for CVE-2005-0039 yet. Limit exposure of the affected software until one is available.

## Is CVE-2005-0039 being exploited?

There is no known exploitation of CVE-2005-0039 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2005-0039 and fix it if it is affected.

What it is: CVE-2005-0039 is a medium-severity vulnerability in n/a, published on 10 May 2005. 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-2005-0039 in the wild and no public exploit code.

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-2005-0039/ (Markdown: https://insights.sbomify.com/CVE-2005-0039/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2005-0039
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2005-0039
- OSV: https://osv.dev/vulnerability/CVE-2005-0039

---
From sbomify Insights: https://insights.sbomify.com/CVE-2005-0039/
Summaries are generated and may contain mistakes; the official description above is the record.