# CVE-2019-10638: Information disclosure in n/a

> Attackers can track devices and recover hashing keys via IP ID collisions in connection-less protocols, enabling user tracking.

- **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:** 5 Jul 2019
- **Updated:** 4 Aug 2024
- **Also known as:** AZL-41613, DEBIAN-CVE-2019-10638, GHSA-wr6f-49rm-hx88, UBUNTU-CVE-2019-10638

## What is CVE-2019-10638?

CVE-2019-10638 is a medium-severity vulnerability in Linux kernel, published on 5 Jul 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

In the Linux kernel before 5.1.7, a device can be tracked by an attacker using the IP ID values the kernel produces for connection-less protocols (e.g., UDP and ICMP). When such traffic is sent to multiple destination IP addresses, it is possible to obtain hash collisions (of indices to the counter array) and thereby obtain the hashing key (via enumeration). An attack may be conducted by hosting a crafted web page that uses WebRTC or gQUIC to force UDP traffic to attacker-controlled IP addresses.

Weakness: CWE-326 (Inadequate Encryption Strength)

## Which versions are affected by CVE-2019-10638?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2019-10638?

Upgrade to a fixed version.

## Is CVE-2019-10638 being exploited?

There is no known exploitation of CVE-2019-10638 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-10638 and fix it if it is affected.

What it is: CVE-2019-10638 is a medium-severity vulnerability in Linux kernel, published on 5 Jul 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-2019-10638 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2019-10638/ (Markdown: https://insights.sbomify.com/CVE-2019-10638/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-10638
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-10638
- OSV: https://osv.dev/vulnerability/CVE-2019-10638

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-10638/
Summaries are generated and may contain mistakes; the official description above is the record.