# CVE-2007-5638: Weak cryptography in n/a

> Remote attackers can guess RUDP IDs to spoof messages and eavesdrop on calls due to weak entropy in the ID field.

- **Severity:** Medium 4.3 (`AV:N/AC:M/Au:N/C:P/I:N/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:** 23 Oct 2007
- **Updated:** 7 Aug 2024
- **Also known as:** GHSA-h59f-qgvv-5qq2

## What is CVE-2007-5638?

CVE-2007-5638 is a medium-severity vulnerability in n/a, published on 23 Oct 2007. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Nortel UNIStim IP Softphone 2050, IP Phone 1140E, and additional Nortel products from the IP Phone, Business Communications Manager (BCM), and other product lines, use only 65536 different values in the 32-bit ID number field of an RUDP datagram, which makes it easier for remote attackers to guess the RUDP ID and spoof messages.  NOTE: this can be leveraged for an eavesdropping attack by sending many Open Audio Stream messages.

Weakness: CWE-310, CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2007-5638?

It affects 9 products.


Products: Nortel Business Communications Manager, Nortel Centrex Ip Client Manager, Nortel Centrex Ip Element Manager, Nortel Meridian Option 11c, Nortel Meridian Option 51c, Nortel Meridian Option 61c, Nortel Meridian Option 81c, Nortel Meridian Sl100, Nortel Mobile Voice Client 2050.

## How do I fix CVE-2007-5638?

No fix has been published for CVE-2007-5638 yet. Limit exposure of the affected software until one is available.

## Is CVE-2007-5638 being exploited?

There is no known exploitation of CVE-2007-5638 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2007-5640](https://insights.sbomify.com/CVE-2007-5640/): Denial of service in n/a (high 7.1)
- [CVE-2007-5637](https://insights.sbomify.com/CVE-2007-5637/): Information disclosure in n/a (medium 4.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2007-5638 and fix it if it is affected.

What it is: CVE-2007-5638 is a medium-severity vulnerability in n/a, published on 23 Oct 2007. 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-2007-5638 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-2007-5638/ (Markdown: https://insights.sbomify.com/CVE-2007-5638/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2007-5638
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2007-5638
- OSV: https://osv.dev/vulnerability/CVE-2007-5638

---
From sbomify Insights: https://insights.sbomify.com/CVE-2007-5638/
Summaries are generated and may contain mistakes; the official description above is the record.