A flaw was found in all python-ecdsa versions before 0.13.3, where it did not correctly verify whether signatures used DER encoding. Without this verification, a malformed signature could be accepted, making the signature malleable. Without proper verification, an attacker could use a malleable signature to create false transactions.
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-14859
https://github.com/warner/python-ecdsa/releases/tag/python-ecdsa-0.13.3
Source: MITRE
Published: 2020-01-02
Updated: 2021-08-04
Type: CWE-347
Base Score: 6.4
Vector: AV:N/AC:L/Au:N/C:P/I:P/A:N
Impact Score: 4.9
Exploitability Score: 10
Severity: MEDIUM
Base Score: 9.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Impact Score: 5.2
Exploitability Score: 3.9
Severity: CRITICAL