TenderMint from version 0.33.0 and before version 0.33.6 allows block proposers to include signatures for the wrong block. This may happen naturally if you start a network, have it run for some time and restart it (**without changing chainID**). A malicious block proposer (even with a minimal amount of stake) can use this vulnerability to completely halt the network. This issue is fixed in Tendermint 0.33.6 which checks all the signatures are for the block with 2/3+ majority before creating a commit.
CWE-347
CVE-2020-15093
The tough library (Rust/crates.io) prior to version 0.7.1 does not properly verify the threshold of cryptographic signatures. It allows an attacker to duplicate a valid signature in order to circumvent TUF requiring a minimum threshold of unique signatures before the metadata is considered valid. A fix is available in version 0.7.1. CVE-2020-6174 is assigned to the same vulnerability in the TUF reference implementation.
CVE-2020-14966
An issue was discovered in the jsrsasign package through 8.0.18 for Node.js. It allows a malleability in ECDSA signatures by not checking overflows in the length of a sequence and ‘0’ characters appended or prepended to an integer. The modified signatures are verified as valid. This could have a security-relevant impact if an application relied on a single canonical signature.
CVE-2020-1464
A spoofing vulnerability exists when Windows incorrectly validates file signatures, aka ‘Windows Spoofing Vulnerability’.
CVE-2020-14515
CodeMeter (All versions prior to 6.90 when using CmActLicense update files with CmActLicense Firm Code) has an issue in the license-file signature checking mechanism, which allows attackers to build arbitrary license files, including forging a valid license file as if it were a valid license file of an existing vendor. Only CmActLicense update files with CmActLicense Firm Code are affected.
CVE-2020-14365
A flaw was found in the Ansible Engine, in ansible-engine 2.8.x before 2.8.15 and ansible-engine 2.9.x before 2.9.13, when installing packages using the dnf module. GPG signatures are ignored during installation even when disable_gpg_check is set to False, which is the default behavior. This flaw leads to malicious packages being installed on the system and arbitrary code executed via package installation scripts. The highest threat from this vulnerability is to integrity and system availability.