Improper Verification of Cryptographic Signature

A vulnerability was detected in PuTTY 0.83. Affected is the function eddsa_verify of the file crypto/ecc-ssh.c of the component Ed25519 Signature Handler. The manipulation results in improper verification of cryptographic signature. The attack may be performed from remote. The attack requires a high level of complexity. The exploitability is told to be difficult. The exploit is now public and may be used. The real existence of this vulnerability is still doubted at the moment. The patch is identified as af996b5ec27ab79bae3882071b9d6acf16044549. It is advisable to implement a patch to correct this issue. The vendor was contacted early, responded in a very professional manner and quickly released a patch for the affected product. However, at the moment there is no proof that this flaw might have any real-world impact.Show less

A flaw has been found in janmojzis tinyssh up to 20250501. Impacted is an unknown function of the file tinyssh/crypto_sign_ed25519_tinyssh.c of the component Ed25519 Signature Handler. This manipulation causes improper verification of cryptographic signature. The attack is restricted to local execution. The attack's complexity is rated as high. The exploitability is considered difficult. The exploit has been published and may be used. Upgrading to version 20260301 is recommended to address this issue. Patch name: 9c87269607e0d7d20174df742accc49c042cff17. Upgrading the affected component is recommended.Show less

A vulnerability was identified in Yi Technology YI Home Camera 2 2.1.1_20171024151200. This impacts an unknown function of the file home/web/ipc of the component HTTP Firmware Update Handler. The manipulation leads to improper verification of cryptographic signature. The attack is possible to be carried out remotely. The complexity of an attack is rather high. The exploitability is said to be difficult. The exploit is publicly available and might be used. The vendor was contacted early about this disclosure but did not respond in any way.Show less

JetKVM prior to 0.5.4 does not verify the authenticity of downloaded firmware files. An attacker-in-the-middle or a compromised update server could modify the firmware and the corresponding SHA256 hash to pass verification.Show less

A condition in the ScreenConnect server component may allow an actor with access to server-level cryptographic material used for authentication to obtain unauthorized access, including elevated privileges, in certain scenarios. ScreenConnect host and guest client agents are not independently affected by this CVE.Show less

Versions of the package sjcl before 1.0.9 are vulnerable to Improper Verification of Cryptographic Signature due to missing point-on-curve validation in sjcl.ecc.basicKey.publicKey(). An attacker can recover a victim's ECDH private key by sending crafted off-curve public keys and observing ECDH outputs. The dhJavaEc() function directly returns the raw x-coordinate of the scalar multiplication result (no hashing), providing a plaintext oracle without requiring any decryption feedback.Show less

Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to version 1.6.9, a JWK Header Injection vulnerability in authlib's JWS implementation allows an unauthenticated attacker to forge arbitrary JWT tokens that pass signature verification. When key=None is passed to any JWS deserialization function, the library extracts and uses the cryptographic key embedded in the attacker-controlled JWT jwk header field. An attacker can sign a token with their own private key, embed the matching public key in the header, and have the server accept the forged token as cryptographically valid — bypassing authentication and authorization entirely. This issue has been patched in version 1.6.9.Show less

Philips Hue Bridge hk_hap Ed25519 Signature Verification Authentication Bypass Vulnerability. This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of Philips Hue Bridge. Authentication is not required to exploit this vulnerability. The specific flaw exists within the ed25519_sign_open function. The issue results from improper verification of a cryptographic signature. An attacker can leverage this vulnerability to bypass authentication on the system. Was ZDI-CAN-28480.Show less

Go ShangMi (Commercial Cryptography) Library (GMSM) is a cryptographic library that covers the Chinese commercial cryptographic public algorithms SM2/SM3/SM4/SM9/ZUC. Prior to 0.41.1, the current SM9 decryption implementation contains an infinity-point ciphertext forgery vulnerability. The root cause is that, during decryption, the elliptic-curve point C1 in the ciphertext is only deserialized and checked to be on the curve, but the implementation does not explicitly reject the point at infinity. In the current implementation, an attacker can construct C1 as the point at infinity, causing the bilinear pairing result to degenerate into the identity element in the GT group. As a result, a critical part of the key derivation input becomes a predictable constant. An attacker who only knows the target user's UID can derive the decryption key material and then forge a ciphertext that passes the integrity check. This vulnerability is fixed in 0.41.1.Show less

HCL AION is affected by a vulnerability where offering images are not digitally signed. Lack of image signing may allow the use of unverified or tampered images, potentially leading to security risks such as integrity compromise or unintended behavior in the systemShow less

PyJWT is a JSON Web Token implementation in Python. Prior to 2.12.0, PyJWT does not validate the crit (Critical) Header Parameter defined in RFC 7515 §4.1.11. When a JWS token contains a crit array listing extensions that PyJWT does not understand, the library accepts the token instead of rejecting it. This violates the MUST requirement in the RFC. This vulnerability is fixed in 2.12.0.Show less

Misskey is an open source, federated social media platform. All Misskey servers prior to 2026.3.1 contain a vulnerability that allows bypassing HTTP signature verification. Although this is a vulnerability related to federation, it affects all servers regardless of whether federation is enabled or disabled. This vulnerability is fixed in 2026.3.1.Show less

A vulnerability was determined in mkj Dropbear up to 2025.89. Impacted is the function unpackneg of the file src/curve25519.c of the component S Range Check. This manipulation causes improper verification of cryptographic signature. The attack can be initiated remotely. The attack is considered to have high complexity. The exploitability is considered difficult. The actual existence of this vulnerability is currently in question. Patch name: fdec3c90a15447bd538641d85e5a3e3ac981011d. To fix this issue, it is recommended to deploy a patch. The project maintainer explains: "Signature Malleability is not exploitable in SSH protocol. (...) [A] PoC doesn't exist for SSH implementation, but rather it's against the internal API."Show less

Authlib is a Python library which builds OAuth and OpenID Connect servers. From version 1.6.5 to before version 1.6.7, previous tests involving passing a malicious JWT containing alg: none and an empty signature was passing the signature verification step without any changes to the application code when a failure was expected.. This issue has been patched in version 1.6.7.Show less

pac4j-jwt versions prior to 4.5.9, 5.7.9, and 6.3.3 contain an authentication bypass vulnerability in JwtAuthenticator when processing encrypted JWTs that allows remote attackers to forge authentication tokens. Attackers who possess the server's RSA public key can create a JWE-wrapped PlainJWT with arbitrary subject and role claims, bypassing signature verification to authenticate as any user including administrators.Show less