How severe is CVE-2021-32489?

CVE-2021-32489 has a CVSS 3.x base score of 4.4, rated medium severity. It is exploitable over network with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-32489 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-32489?

CVE-2021-32489 affects Yubico Yubihsm-shell. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-32489?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-32489 published?

CVE-2021-32489 was published on 2021-05-10 and last updated on 2026-06-17.

CVE-2021-32489

CVE-2021-32489 is a medium-severity vulnerability in Yubico Yubihsm-shell with a CVSS 3.x base score of 4.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-190.

Key facts

Severity: Medium (CVSS 3.x base score 4.4)
CVSS v2: 3.5
EPSS exploit prediction: 1% (56th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-190
Affected product: Yubico Yubihsm-shell
Published: 2021-05-10
Last modified: 2026-06-17

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 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.

Frequently asked questions

What is 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.
How severe is CVE-2021-32489?: CVE-2021-32489 has a CVSS 3.x base score of 4.4, rated medium severity. It is exploitable over network with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-32489 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-32489?: CVE-2021-32489 affects Yubico Yubihsm-shell. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-32489?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-32489 published?: CVE-2021-32489 was published on 2021-05-10 and last updated on 2026-06-17.

References

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

Affected products (1)

cpe:2.3:a:yubico:yubihsm-shell:*:*:*:*:*:*:*:*

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