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.

It was found that Keycloak's SAML broker, versions up to 6.0.1, did not verify missing message signatures. If an attacker modifies the SAML Response and removes the <Signature> sections, the message is still accepted, and the message can be modified. An attacker could use this flaw to impersonate other users and gain access to sensitive information.

It was found that Spacewalk, all versions through 2.9, did not safely compute client token checksums. An attacker with a valid, but expired, authenticated set of headers could move some digits around, artificially extending the session validity without modifying the checksum.

An issue was discovered in D-Bus before 1.12.24, 1.13.x and 1.14.x before 1.14.4, and 1.15.x before 1.15.2. An authenticated attacker can cause dbus-daemon and other programs that use libdbus to crash when receiving a message with certain invalid type signatures.

In mutt and neomutt the In-Reply-To email header field is not protected by cryptographic signing which allows an attacker to reuse an unencrypted but signed email message to impersonate the original sender.

ecdsautils is a tiny collection of programs used for ECDSA (keygen, sign, verify). `ecdsa_verify_[prepare_]legacy()` does not check whether the signature values `r` and `s` are non-zero. A signature consisting only of zeroes is always considered valid, making it trivial to forge signatures. Requiring multiple signatures from different public keys does not mitigate the issue: `ecdsa_verify_list_legacy()` will accept an arbitrary number of such forged signatures. Both the `ecdsautil verify` CLI command and the libecdsautil library are affected. The issue has been fixed in ecdsautils 0.4.1. All older versions of ecdsautils (including versions before the split into a library and a CLI utility) are vulnerable.

In Bouncy Castle JCE Provider version 1.55 and earlier the DSA does not fully validate ASN.1 encoding of signature on verification. It is possible to inject extra elements in the sequence making up the signature and still have it validate, which in some cases may allow the introduction of 'invisible' data into a signed structure.

The App::cpanminus package 1.7044 for Perl allows Signature Verification Bypass.

go-tuf is a Go implementation of The Update Framework (TUF). Starting in version 2.0.0 and prior to version 2.3.1, a compromised or misconfigured TUF repository can have the configured value of signature thresholds set to 0, which effectively disables signature verification. This can lead to unauthorized modification to TUF metadata files is possible at rest, or during transit as no integrity checks are made. Version 2.3.1 fixes the issue. As a workaround, always make sure that the TUF metadata roles are configured with a threshold of at least 1.

uthenticode is a small cross-platform library for partially verifying Authenticode digital signatures. Versions of uthenticode prior to the 2.x series did not check Extended Key Usages in certificates, in violation of the Authenticode X.509 certificate profile. As a result, a malicious user could produce a "signed" PE file that uthenticode would verify and consider valid using an X.509 certificate that isn't entitled to produce code signatures (e.g., a SSL certificate). By design, uthenticode does not perform full-chain validation. However, the absence of EKU validation was an unintended oversight. The 2.0.0 release series includes EKU checks. There are no workarounds to this vulnerability.

A Security Bypass vulnerability exists in Ubuntu Cobbler before 2,2,2 in the cobbler-ubuntu-import script due to an error when verifying the GPG signature.

MinIO is an open-source high performance object storage service and it is API compatible with Amazon S3 cloud storage service. In MinIO before version RELEASE.2021-03-17T02-33-02Z, there is a vulnerability which enables MITM modification of request bodies that are meant to have integrity guaranteed by chunk signatures. In a PUT request using aws-chunked encoding, MinIO ordinarily verifies signatures at the end of a chunk. This check can be skipped if the client sends a false chunk size that is much greater than the actual data sent: the server accepts and completes the request without ever reaching the end of the chunk + thereby without ever checking the chunk signature. This is fixed in version RELEASE.2021-03-17T02-33-02Z. As a workaround one can avoid using "aws-chunked" encoding-based chunk signature upload requests instead use TLS. MinIO SDKs automatically disable chunked encoding signature when the server endpoint is configured with TLS.

LINE for Android version 5.0.2 and earlier and LINE for iOS version 5.0.0 and earlier are vulnerable to MITM (man-in-the-middle) attack since the application allows non-SSL/TLS communications. As a result, any API may be invoked from a script injected by a MITM (man-in-the-middle) attacker.

LINE@ for Android version 1.0.0 and LINE@ for iOS version 1.0.0 are vulnerable to MITM (man-in-the-middle) attack since the application allows non-SSL/TLS communications. As a result, any API may be invoked from a script injected by a MITM (man-in-the-middle) attacker.

Lotus is an Implementation of the Filecoin protocol written in Go. BLS signature validation in lotus uses blst library method VerifyCompressed. This method accepts signatures in 2 forms: "serialized", and "compressed", meaning that BLS signatures can be provided as either of 2 unique byte arrays. Lotus block validation functions perform a uniqueness check on provided blocks. Two blocks are considered distinct if the CIDs of their blockheader do not match. The CID method for blockheader includes the BlockSig of the block. The result of these issues is that it would be possible to punish miners for valid blocks, as there are two different valid block CIDs available for each block, even though this must be unique. By switching from the go based `blst` bindings over to the bindings in `filecoin-ffi`, the code paths now ensure that all signatures are compressed by size and the way they are deserialized. This happened in https://github.com/filecoin-project/lotus/pull/5393.

DELL ECS prior to 3.8.0.2 contains an improper verification of cryptographic signature vulnerability. A network attacker with an ability to intercept the request could potentially exploit this vulnerability to modify the body data of the request.

libgit2 is a cross-platform, linkable library implementation of Git. When using an SSH remote with the optional libssh2 backend, libgit2 does not perform certificate checking by default. Prior versions of libgit2 require the caller to set the `certificate_check` field of libgit2's `git_remote_callbacks` structure - if a certificate check callback is not set, libgit2 does not perform any certificate checking. This means that by default - without configuring a certificate check callback, clients will not perform validation on the server SSH keys and may be subject to a man-in-the-middle attack. Users are encouraged to upgrade to v1.4.5 or v1.5.1. Users unable to upgrade should ensure that all relevant certificates are manually checked.

In the pre connection stage, an improper enforcement of message integrity vulnerability exists in BIG-IP Edge Client for Windows and Mac OS.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

A message-forgery issue was discovered in crypto/openpgp/clearsign/clearsign.go in supplementary Go cryptography libraries 2019-03-25. According to the OpenPGP Message Format specification in RFC 4880 chapter 7, a cleartext signed message can contain one or more optional "Hash" Armor Headers. The "Hash" Armor Header specifies the message digest algorithm(s) used for the signature. However, the Go clearsign package ignores the value of this header, which allows an attacker to spoof it. Consequently, an attacker can lead a victim to believe the signature was generated using a different message digest algorithm than what was actually used. Moreover, since the library skips Armor Header parsing in general, an attacker can not only embed arbitrary Armor Headers, but also prepend arbitrary text to cleartext messages without invalidating the signatures.

Cargo is a Rust package manager. The Rust Security Response WG was notified that Cargo did not perform SSH host key verification when cloning indexes and dependencies via SSH. An attacker could exploit this to perform man-in-the-middle (MITM) attacks. This vulnerability has been assigned CVE-2022-46176. All Rust versions containing Cargo before 1.66.1 are vulnerable. Note that even if you don't explicitly use SSH for alternate registry indexes or crate dependencies, you might be affected by this vulnerability if you have configured git to replace HTTPS connections to GitHub with SSH (through git's [`url.<base>.insteadOf`][1] setting), as that'd cause you to clone the crates.io index through SSH. Rust 1.66.1 will ensure Cargo checks the SSH host key and abort the connection if the server's public key is not already trusted. We recommend everyone to upgrade as soon as possible.