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CVE-2020-13131

MEDIUMCVSS 4.3/10EPSS 0.49%

Last modified

CVE-2020-13131 is a medium-severity vulnerability rated 4.3/10 on the CVSS scale. An issue was discovered in Yubico libykpiv before 2.1.0. lib/util.c in this library (which is included in yubico-piv-tool) does not properly check embedded length fields during device communication. EPSS estimates a 0.49% chance of exploitation in the next 30 days.

Description

An issue was discovered in Yubico libykpiv before 2.1.0. lib/util.c in this library (which is included in yubico-piv-tool) does not properly check embedded length fields during device communication. A malicious PIV token can misreport the returned length fields during RSA key generation. This will cause stack memory to be copied into heap allocated memory that gets returned to the caller. The leaked memory could include PINs, passwords, key material, and other sensitive information depending on the integration. During further processing by the caller, this information could leak across trust boundaries. Note that RSA key generation is triggered by the host and cannot directly be triggered by the token.

Metrics

CVSS 3.1
4.3/10

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

EPSS Probability
0.49%

38.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
YubicoLibykpiv< 2.1.0
YubicoPiv Tool Manager< 2.0.0
YubicoYubikey Smart Card Minidriver<= 4.1.0.172

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2020-13131?
An issue was discovered in Yubico libykpiv before 2.1.0. lib/util.c in this library (which is included in yubico-piv-tool) does not properly check embedded length fields during device communication. A malicious PIV token can misreport the returned length fields during RSA key generation. This will cause stack memory to be copied into heap allocated memory that gets returned to the caller. The leaked memory could include PINs, passwords, key material, and other sensitive information depending on the integration. During further processing by the caller, this information could leak across trust boundaries. Note that RSA key generation is triggered by the host and cannot directly be triggered by the token.
How severe is CVE-2020-13131?
CVE-2020-13131 has a CVSS score of 4.3/10 (MEDIUM severity). The EPSS model estimates a 0.49% probability of exploitation in the next 30 days.
How do I fix CVE-2020-13131?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-13131?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST