# CVE-2018-12402: Information disclosure in Firefox

> A malicious page can leak Windows credentials and bypass SameSite cookie restrictions when a user saves the page, exposing sensitive data.

- **Severity:** Medium 6.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 28 Feb 2019
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-ggqr-5458-x5c8, UBUNTU-CVE-2018-12402

## What is CVE-2018-12402?

CVE-2018-12402 is a medium-severity vulnerability in Canonical Ubuntu Linux, published on 28 Feb 2019. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

The internal WebBrowserPersist code does not use correct origin context for a resource being saved. This manifests when sub-resources are loaded as part of "Save Page As..." functionality. For example, a malicious page could recover a visitor's Windows username and NTLM hash by including resources otherwise unreachable to the malicious page, if they can convince the visitor to save the complete web page. Similarly, SameSite cookies are sent on cross-origin requests when the "Save Page As..." menu item is selected to save a page, which can result in saving the wrong version of resources based on those cookies. This vulnerability affects Firefox < 63.

Weakness: CWE-346 (Origin Validation Error)

## Which versions are affected by CVE-2018-12402?

It affects 2 products.


Products: Canonical Ubuntu Linux, Mozilla Firefox.

## How do I fix CVE-2018-12402?

Upgrade to a fixed version.

## Is CVE-2018-12402 being exploited?

There is no known exploitation of CVE-2018-12402 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-2018-12402 and fix it if it is affected.

What it is: CVE-2018-12402 is a medium-severity vulnerability in Canonical Ubuntu Linux, published on 28 Feb 2019. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2018-12402 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-2018-12402/ (Markdown: https://insights.sbomify.com/CVE-2018-12402/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-12402
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-12402
- OSV: https://osv.dev/vulnerability/CVE-2018-12402

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-12402/
Summaries are generated and may contain mistakes; the official description above is the record.