Integer overflow in Yubico Yubihsm-Shell
CVE-2021-32489
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.
Vulnerability class: Integer Overflow
EPSS: 0.009 (56.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.4 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Yubico Yubihsm-shell
- N/a — versions n/a
Weakness classification (CWE)
Public proof-of-concept exploits
References
- cve@mitre.org (Exploit, Third Party Advisory, x_refsource_MISC)
Frequently asked questions
- What is CVE-2021-32489?
- CVE-2021-32489 is a medium-severity vulnerability in Yubico Yubihsm-Shell, classified under Integer Overflow or Wraparound. CVSS score: 4.4/10. Published 2021-05-10.
- How severe is CVE-2021-32489?
- Medium severity. CVSS v3 base score is 4.4 out of 10.
- Is CVE-2021-32489 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.