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CVE-2017-18021: Qtpass: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

CVE-2017-18021 is rated critical with a CVSS v3.0 base score of 9.8 and affects Qtpass. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability description

It was discovered that QtPass before 1.2.1, when using the built-in password generator, generates possibly predictable and enumerable passwords. This only applies to the QtPass GUI.

Severity breakdown

CVSS v3.0 9.8: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

• Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
• Attack complexity: Low. No special conditions; the attack can be repeated reliably.
• Privileges required: None. No account or prior access is needed.
• User interaction: None. No action from any user is needed.
• Scope: Unchanged. Impact stays within the vulnerable component.
• Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
• Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
• Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-338: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

The product uses a Pseudo-Random Number Generator (PRNG) in a security context, but the PRNG's algorithm is not cryptographically strong.

Affected products

• Qtpass: before 1.2.1

References

• https://lists.zx2c4.com/pipermail/password-store/2018-January/003165.html
• https://qtpass.org/
• https://github.com/IJHack/QtPass/issues/338
• https://github.com/IJHack/QtPass/releases/tag/v1.2.1