A side-channel issue was discovered in Botan before 2.9.0.
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- No fix listed
Attack profile from CVSS 3.0 · NVD. Fix status from CNA.
Summary
A side-channel issue was discovered in Botan before 2.9.0. An attacker capable of precisely measuring the time taken for ECC key generation may be able to derive information about the high bits of the secret key, as the function to derive the public point from the secret scalar uses an unblinded Montgomery ladder whose loop iteration count depends on the bitlength of the secret. This issue affects only key generation, not ECDSA signatures or ECDH key agreement.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2018-20187
- 2026-10-03 Alias added: GHSA-g9j4-hp3j-g668
References
More randombit Botan vulnerabilities
- TI-2024-33818 Botan before 3.6.0, when certain GCC versions are used, has a compiler-induced… CVSS 3.1MEDIUM 5.9
- TI-2024-33817 Botan before 3.6.0, when certain LLVM versions are used, has compiler-induced… CVSS 3.1MEDIUM 5.9
- TI-2016-02004 Integer overflow in the PointGFp constructor in Botan before 1.10.11 and 1.11.x before… CVSS 3.0CRITICAL 9.8
- TI-2016-02005 Heap-based buffer overflow in the P-521 reduction function in Botan 1.11.x before 1.11.27… CVSS 3.0CRITICAL 9.8
- TI-2026-26828 Botan has a certificate authentication bypass due to trust anchor confusion CVSS 4.0CRITICAL 9.3
- TI-2016-07479 In Botan 1.8.0 through 1.11.33, when decoding BER data an integer overflow could occur… CVSS 3.0CRITICAL 9.8
Sources
- CVE-2018-20187 · CVE Program
- CVE-2018-20187 · NVD
- FIRST EPSS
- GHSA-g9j4-hp3j-g668 · GitHub Advisory Database · CC BY 4.0
- CVE-2018-20187 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences