# CVE-2006-4790: Security feature bypass in n/a

> Remote attackers can forge PKCS #1 v1.5 signatures using RSA keys with exponent 3, bypassing certificate verification in GnuTLS.

- **Severity:** Medium 5.0 (`AV:N/AC:L/Au:N/C:N/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:** Yes
- **Published:** 14 Sep 2006
- **Updated:** 7 Aug 2024
- **Also known as:** DSA-1182-1, GHSA-fjc3-r8f9-57p5, RHSA-2006:0680

## What is CVE-2006-4790?

CVE-2006-4790 is a medium-severity vulnerability in Gnu Gnutls, published on 14 Sep 2006. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

verify.c in GnuTLS before 1.4.4, when using an RSA key with exponent 3, does not properly handle excess data in the digestAlgorithm.parameters field when generating a hash, which allows remote attackers to forge a PKCS #1 v1.5 signature that is signed by that RSA key and prevents GnuTLS from correctly verifying X.509 and other certificates that use PKCS, a variant of CVE-2006-4339.

## Which versions are affected by CVE-2006-4790?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `gnutls` | Red Hat:enterprise_linux:4::as | All versions | 0:1.0.20-3.2.3 |
| `gnutls-debuginfo` | Red Hat:enterprise_linux:4::as | All versions | 0:1.0.20-3.2.3 |
| `gnutls-devel` | Red Hat:enterprise_linux:4::as | All versions | 0:1.0.20-3.2.3 |
| `gnutls` | Red Hat:enterprise_linux:4::desktop | All versions | 0:1.0.20-3.2.3 |
| `gnutls-debuginfo` | Red Hat:enterprise_linux:4::desktop | All versions | 0:1.0.20-3.2.3 |
| `gnutls-devel` | Red Hat:enterprise_linux:4::desktop | All versions | 0:1.0.20-3.2.3 |
| `gnutls` | Red Hat:enterprise_linux:4::es | All versions | 0:1.0.20-3.2.3 |
| `gnutls-debuginfo` | Red Hat:enterprise_linux:4::es | All versions | 0:1.0.20-3.2.3 |
| `gnutls-devel` | Red Hat:enterprise_linux:4::es | All versions | 0:1.0.20-3.2.3 |
| `gnutls` | Red Hat:enterprise_linux:4::ws | All versions | 0:1.0.20-3.2.3 |
| `gnutls-debuginfo` | Red Hat:enterprise_linux:4::ws | All versions | 0:1.0.20-3.2.3 |
| `gnutls-devel` | Red Hat:enterprise_linux:4::ws | All versions | 0:1.0.20-3.2.3 |

Products: Gnu Gnutls.

## How do I fix CVE-2006-4790?

Upgrade to a fixed version.

## Is CVE-2006-4790 being exploited?

There is no known exploitation of CVE-2006-4790 in the wild and no public exploit code.

## Other vulnerabilities in Gnu Gnutls

- [CVE-2008-1948](https://insights.sbomify.com/CVE-2008-1948/): Memory corruption in n/a (critical 10.0)
- [CVE-2017-5334](https://insights.sbomify.com/CVE-2017-5334/): Use after free in n/a (critical 9.8)
- [CVE-2017-5336](https://insights.sbomify.com/CVE-2017-5336/): Memory corruption in n/a (critical 9.8)
- [CVE-2017-5337](https://insights.sbomify.com/CVE-2017-5337/): Memory corruption in n/a (critical 9.8)
- [CVE-2008-1949](https://insights.sbomify.com/CVE-2008-1949/): Null dereference in n/a (critical 9.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2006-4790 and fix it if it is affected.

What it is: CVE-2006-4790 is a medium-severity vulnerability in Gnu Gnutls, published on 14 Sep 2006. 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-2006-4790 in the wild and no public exploit code.

Affected product: Gnu Gnutls. 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-2006-4790/ (Markdown: https://insights.sbomify.com/CVE-2006-4790/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2006-4790
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2006-4790
- OSV: https://osv.dev/vulnerability/CVE-2006-4790

---
From sbomify Insights: https://insights.sbomify.com/CVE-2006-4790/
Summaries are generated and may contain mistakes; the official description above is the record.