CVE-2021-32489

10.05.2021, 22:15

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 because response_msg.st.len=8 can be accepted but triggers an integer overflow, which causes CRYPTO_cbc128_decrypt (in OpenSSL) to encounter an undersized buffer and experience a segmentation fault. The yubihsm-shell project is included in the YubiHSM 2 SDK product.

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	NIST	4.4 MEDIUM	NETWORK	HIGH	HIGH	CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H
mitre	CNA	4.4 MEDIUM	NETWORK	HIGH	HIGH	CVSS:3.1/AC:H/AV:N/A:H/C:N/I:N/PR:H/S:U/UI:N
CVE	ADP	---				---

Base Score

CVSS 3.x

EPSS Score

Percentile: 65%

Vendor	Product	Version
yubico	yubihsm-shell	𝑥 ≤ 2.0.3

𝑥

= Vulnerable software versions

Known Exploits!

Common Weakness Enumeration

CWE-190 - Integer Overflow or Wraparound
The software performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control.

References

https://blog.inhq.net/posts/yubico-libyubihsm-vuln2/#second-attack-variant-cve-pending