# CVE-2019-11743: Information disclosure in Firefox

> Attackers can exploit timing side-channels to expose cross-origin history information due to non-compliant navigation timing events.

- **Severity:** Low 3.7 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/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:** Yes
- **Published:** 27 Sep 2019
- **Updated:** 4 Aug 2024
- **Also known as:** DEBIAN-CVE-2019-11743, GHSA-98fg-hp5j-cm68, UBUNTU-CVE-2019-11743

## What is CVE-2019-11743?

CVE-2019-11743 is a low-severity vulnerability in Mozilla Firefox, published on 27 Sep 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Navigation events were not fully adhering to the W3C's "Navigation-Timing Level 2" draft specification in some instances for the unload event, which restricts access to detailed timing attributes to only be same-origin. This resulted in potential cross-origin information exposure of history through timing side-channel attacks. This vulnerability affects Firefox < 69, Thunderbird < 68.1, Thunderbird < 60.9, Firefox ESR < 60.9, and Firefox ESR < 68.1.

Weakness: CWE-203 (Observable Discrepancy)

## Which versions are affected by CVE-2019-11743?

It affects 3 products.


Products: Mozilla Firefox, Mozilla Firefox Esr, Mozilla Thunderbird.

## How do I fix CVE-2019-11743?

Upgrade to a fixed version.

## Is CVE-2019-11743 being exploited?

There is no known exploitation of CVE-2019-11743 in the wild and no public exploit code.

## Other vulnerabilities in Mozilla Firefox

- [CVE-2019-11708](https://insights.sbomify.com/CVE-2019-11708/): Mozilla Firefox and Thunderbird Sandbox Escape (critical 10.0, exploited in the wild)
- [CVE-2010-3765](https://insights.sbomify.com/CVE-2010-3765/): Mozilla Multiple Products Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2022-26486](https://insights.sbomify.com/CVE-2022-26486/): Mozilla Firefox Use-After-Free (critical 9.6, exploited in the wild)
- [CVE-2022-26485](https://insights.sbomify.com/CVE-2022-26485/): Mozilla Firefox Use-After-Free (high 8.8, exploited in the wild)
- [CVE-2019-11707](https://insights.sbomify.com/CVE-2019-11707/): Mozilla Firefox and Thunderbird Type Confusion (high 8.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-11743 and fix it if it is affected.

What it is: CVE-2019-11743 is a low-severity vulnerability in Mozilla Firefox, published on 27 Sep 2019. 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-2019-11743 in the wild and no public exploit code.

Affected product: Mozilla Firefox. 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-2019-11743/ (Markdown: https://insights.sbomify.com/CVE-2019-11743/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-11743
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-11743
- OSV: https://osv.dev/vulnerability/CVE-2019-11743

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-11743/
Summaries are generated and may contain mistakes; the official description above is the record.