CVE-2018-12437
Updated libtomcrypt packages fix security vulnerability
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.
Attack profile
How easy it is to exploit
- Attack vector
- Physical
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
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.
- Record
CVE-2018-12437- CVSS 3.1
- 4.9 Medium
CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N - CVSS 2.0
- 1.9 Low
AV:L/AC:M/Au:N/C:P/I:N/A:N - Weakness
- CWE-200
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2018-12437- Updated
- 2026-11-02
EUVDEUVD-2018-4408 No score
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.
- Record
EUVD-2018-4408- Updated
- 2026-11-03
OSV
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.
- Record
CVE-2018-12437- CVSS 3.1
- 4.9 Medium
CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N - Updated
- 2026-11-02
OSVDEBIAN-CVE-2018-12437
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.
- Record
DEBIAN-CVE-2018-12437- CVSS 3.1
- 4.9 Medium
CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N - Updated
- 2026-11-02
OSVUBUNTU-CVE-2018-12437
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.
- Record
UBUNTU-CVE-2018-12437- CVSS 3.1
- 4.9 Medium
CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N - CVSS 3.0
- 4.9 Medium
CVSS:3.0/AV:P/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N - Updated
- 2026-11-02
OSVMGASA-2018-0339 No score
Updated libtomcrypt packages fix security vulnerability
libtomcrypt has been updated to secure it against two security vulnerabilities.
A problem in the ASN.1 parser could cause a stack overflow and a resulting denial of service when parsing deeply recursive ASN.1 types (CVE-2018-0739).
An attacker capable of triggering signatures and mounting a side channel attack against a victim can extract an ECDSA key in a practical amount of time (CVE-2018-12437).
- Record
MGASA-2018-0339- Updated
- 2026-11-02
OSVopenSUSE-SU-2024:11003-1 No score
libtomcrypt-devel-1.18.2-2.10 on GA media
These are all security issues fixed in the libtomcrypt-devel-1.18.2-2.10 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:11003-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
libtomcryptDebian:12 |
before 1.18.2-1 | 1.18.2-1 |
libtomcryptDebian:13 |
before 1.18.2-1 | 1.18.2-1 |
libtomcryptDebian:14 |
before 1.18.2-1 | 1.18.2-1 |
libtomcryptMageia:6 |
before 1.17-11.1.mga6 | 1.17-11.1.mga6 |
libtomcryptUbuntu:14.04:LTS |
before 1.17-5ubuntu0.1, plus listed versions 1.17-3.2ubuntu11.17-5 |
1.17-5ubuntu0.1 |
libtomcryptUbuntu:16.04:LTS |
before 1.17-7ubuntu0.1, plus listed versions 1.17-7 |
1.17-7ubuntu0.1 |
libtomcryptUbuntu:18.04:LTS |
before 1.18.1-1ubuntu0.1, plus listed versions 1.17-91.18.0-11.18.1-1 |
1.18.1-1ubuntu0.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2018-12437 is a medium vulnerability (CVSS 4.9) in Libtom Libtomcrypt, published June 15, 2018. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.54%, the 45th percentile. Fixed in libtomcrypt 1.18.2-1.