# CVE-2015-8805: Weak cryptography in n/a

> Incorrect carry propagation in Nettle's P-256 implementation produces wrong outputs, potentially compromising cryptographic operations.

- **Severity:** Critical 9.8 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 23 Feb 2016
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2015-8805, GHSA-pfjj-937g-c323, UBUNTU-CVE-2015-8805

## What is CVE-2015-8805?

CVE-2015-8805 is a critical vulnerability in Canonical Ubuntu Linux, published on 23 Feb 2016. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The ecc_256_modq function in ecc-256.c in Nettle before 3.2 does not properly handle carry propagation and produces incorrect output in its implementation of the P-256 NIST elliptic curve, which allows attackers to have unspecified impact via unknown vectors, a different vulnerability than CVE-2015-8803.

Weakness: CWE-310

## Which versions are affected by CVE-2015-8805?

It affects 4 products.


Products: Canonical Ubuntu Linux, Nettle Project Nettle, Opensuse Leap, Opensuse Opensuse.

## How do I fix CVE-2015-8805?

Upgrade to a fixed version.

## Is CVE-2015-8805 being exploited?

There is no known exploitation of CVE-2015-8805 in the wild and no public exploit code.

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2020-11651](https://insights.sbomify.com/CVE-2020-11651/): SaltStack Salt Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2020-7247](https://insights.sbomify.com/CVE-2020-7247/): OpenSMTPD Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2019-16928](https://insights.sbomify.com/CVE-2019-16928/): Exim Out-of-bounds Write (critical 9.8, exploited in the wild)
- [CVE-2018-6789](https://insights.sbomify.com/CVE-2018-6789/): Exim Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2015-2590](https://insights.sbomify.com/CVE-2015-2590/): Oracle Java SE and Java SE Embedded Remote Code Execution (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2015-8805 and fix it if it is affected.

What it is: CVE-2015-8805 is a critical vulnerability in Canonical Ubuntu Linux, published on 23 Feb 2016. 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-2015-8805 in the wild and no public exploit code.

Affected product: Canonical Ubuntu 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-2015-8805/ (Markdown: https://insights.sbomify.com/CVE-2015-8805/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2015-8805
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2015-8805
- OSV: https://osv.dev/vulnerability/CVE-2015-8805

---
From sbomify Insights: https://insights.sbomify.com/CVE-2015-8805/
Summaries are generated and may contain mistakes; the official description above is the record.