CVE-2026-40097— Smallstep step-ca 输入验证错误漏洞

Step CA affected by an index out of bounds panic in TPM attestation EKU validation

Step CA is an online certificate authority for secure, automated certificate management for DevOps. From 0.24.0 to before 0.30.0-rc3, an attacker can trigger an index out-of-bounds panic in Step CA by sending a crafted attestation key (AK) certificate with an empty Extended Key Usage (EKU) extension during TPM device attestation. When processing a device-attest-01 ACME challenge using TPM attestation, Step CA validates that the AK certificate contains the tcg-kp-AIKCertificate Extended Key Usage OID. During this validation, the EKU extension value is decoded from its ASN.1 representation and the first element is checked. A crafted certificate could include an EKU extension that decodes to an empty sequence, causing the code to panic when accessing the first element of the empty slice. This vulnerability is only reachable when a device-attest-01 ACME challenge with TPM attestation is configured. Deployments not using TPM device attestation are not affected. This vulnerability is fixed in 0.30.0-rc3.

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

对数组索引的验证不恰当

Smallstep step-ca 输入验证错误漏洞

Smallstep step-ca是美国Smallstep公司的一个面向DevOps的安全、自动化证书管理的在线证书颁发机构。 Smallstep step-ca 0.30.0-rc3之前版本存在输入验证错误漏洞，该漏洞源于处理特制证明密钥证书时边界检查不足，可能导致索引越界恐慌。

N/A

N/A