CVE-2021-27217

MEDIUM
Published Mar 4, 20215y ago · Modified Jun 17, 20262w ago
4.4 CVSS 3.1
Medium
Find Similar
Published Mar 4, 2021 5y ago
Last Modified Jun 17, 2026 2w ago

Description

An issue was discovered in the _send_secure_msg() function of Yubico yubihsm-shell through 2.0.3. The function does not correctly validate the embedded length field of an authenticated message received from the device. Out-of-bounds reads performed by aes_remove_padding() can crash the running process, depending on the memory layout. This could be used by an attacker to cause a client-side denial of service. The yubihsm-shell project is included in the YubiHSM 2 SDK product.

CVSS Details

Base Score
4.4
Exploitability
0.7
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network
Attack Complexity High
Privileges Required High
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

No active exploitation signals — not in CISA KEV and no EPSS score yet.

Exploit & Patch Status
Public Exploit Known
No Patch Available

Weaknesses 1

CWE-125 Out-of-bounds Read Memory Safety

Affected Products 1

VendorProductVersionRange
yubicoyubihsm-shell* ≤2.0.3

References 3

  • blog.inhq.net https://blog.inhq.net/posts/yubico-libyubihsm-vuln2
    ExploitThird Party Advisory
  • github.com https://github.com/Yubico/yubihsm-shell/releases
    Release NotesThird Party Advisory
  • yubico.com https://www.yubico.com/support/security-advisories/ysa-2021-01/
    Vendor Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.