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 Problem or ROHNP, related to dsa/dsa.cpp, ec_group/ec_group.cpp, and ecdsa/ecdsa.cpp.
Does this matter?
Lower severity and a low EPSS score (0.49%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.0
- 5.9 MEDIUMCVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N
- EPSS
- 0.49% probability · 42th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-200
- Affected
- botan project/botan
- Source
- cve@mitre.org
EPSS 0.5% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://botan.randombit.net/security.htmlThird Party Advisory
- https://github.com/randombit/botan/commit/48fc8df51d99f9d8ba251219367b3d629cc848e3Patch, Third Party Advisory
- https://www.nccgroup.trust/us/our-research/technical-advisory-return-of-the-hidden-number-problem/Exploit, Third Party Advisory
- https://botan.randombit.net/security.htmlThird Party Advisory
- https://github.com/randombit/botan/commit/48fc8df51d99f9d8ba251219367b3d629cc848e3Patch, Third Party Advisory
- https://www.nccgroup.trust/us/our-research/technical-advisory-return-of-the-hidden-number-problem/Exploit, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.