CVE-2018-14779

A buffer overflow issue was discovered in the Yubico-Piv 1.5.0 smartcard driver. The file lib/ykpiv.c contains the following code in the function `ykpiv_transfer_data()`: {% highlight c %} if(*out_len + recv_len - 2 > max_out) { fprintf(stderr, "Output buffer to small, wanted to write %lu, max was %lu.", *out_len + recv_len - 2, max_out); } if(out_data) { memcpy(out_data, data, recv_len - 2); out_data += recv_len - 2; *out_len += recv_len - 2; } {% endhighlight %} -- it is clearly checked whether the buffer is big enough to hold the data copied using `memcpy()`, but no error handling happens to avoid the `memcpy()` in such cases. This code path can be triggered with malicious data coming from a smartcard.

From the Ubuntu Security Team

It was discovered that libykpiv, a supporting library of the Yubico PIV tool and YubiKey PIV Manager, mishandled specially crafted input. An attacker with a custom-made, malicious USB device could potentially execute arbitrary code on a computer running the Yubico PIV Tool or Yubikey PIV Manager.

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References

• MITRE
• NVD
• Launchpad
• Debian

Related Ubuntu Security Notices (USN)

• USN-4276-1
• Yubico PIV Tool vulnerabilities
• 11 February 2020
• USN-4846-1
• Yubico PIV Tool vulnerabilities
• 15 March 2021

Other references

• https://www.x41-dsec.de/lab/advisories/x41-2018-001-Yubico-Piv/
• https://www.cve.org/CVERecord?id=CVE-2018-14779