# CVE-2018-12437: libtomcrypt1: LibTomCrypt through 1.18.1 allows a memory-cache side-channel attack on ECDSA signatures, aka the Return Of the Hidde...

CVE-2018-12437 is fixed in libtomcrypt1 on 1 platform by libtomcrypt1 1.18.1-1ubuntu0.1 (version 1.18.1-1ubuntu0.1), released June 14, 2018. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2018-12437
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0054
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 14, 2018

## Description

LibTomCrypt through 1.18.1 allows a memory-cache side-channel attack on ECDSA signatures, aka the Return Of the Hidden Number Problem or ROHNP. To discover an ECDSA key, the attacker needs access to either the local machine or a different virtual machine on the same physical host.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | libtomcrypt1 Ubuntu 18.04.6 LTS (bionic) | 1.18.1-1ubuntu0.1 | [libtomcrypt1 1.18.1-1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libtomcrypt1-1.18.1-1ubuntu0.1.md) | Jun 14, 2018 |

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Data as of 2026-11-07T12:40:37Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo