All the vulnerabilities related to the version 0.9.0 of the package
Improper calculations in ECC implementation can trigger a Denial-of-Service (DoS)
When using the non-default "fallback" crypto back-end, ECC operations in node-jose can trigger a Denial-of-Service (DoS) condition, due to a possible infinite loop in an internal calculation. For some ECC operations, this condition is triggered randomly; for others, it can be triggered by malicious input.
The JOSE logic implemented by node-jose usually relies on an external cryptographic library for the underlying cryptographic primitives that JOSE operations require. When WebCrypto or the Node crypto module are available, they are used. When neither of these libraries is available, node-jose includes its own "fallback" implementations of some algorithms based on node-forge, in particular implementations of ECDH and ECDSA.
A various points, these algorithm implementations need to compute to the X coordinate of an elliptic curve point. This is done by calling the getX() method of the object representing the point, which is an alias of the function pointFpGetX() in lib/deps/ecc/math.js.
Computing the X coordinate from the form in which the point is stored requires computing the modular inverse of the Z coordinate, using the modInverse function from the jsbn library (e.g., this.z.modInverse(this.curve.p)). The output of this function call is multiplied by another value before being reduced with the barrettReduce() function.
The root cause of this issue is that the jsbn modInverse function sometimes returns negative results. These results are correct in that they are equivalent mod the relevant modulus, but can be problematic for functions that expect modular operations to always return positive results (in the range [0, p), where p is the modulus).
In particular, while the Barrett reduction algorithm in general can handle negative inputs, the implementation in node-jose explicitly does not. Therefore, while the negative value that is returned by modInverse() is mathematically correct, it leads to an error in barrettReduce() causing an infinite loop which may result in a Denial of Service condition.
For a given prime modulus, we estimate that roughly one in every 2^20 inputs produce a negative modInverse(). This estimate was validated with exhaustive testing on small primes (<30 bits) and randomized testing with regard to the P-256 prime.
This issue is only present in situations where the "fallback" cryptographic implementation is being used, i.e., situations where neither WebCrypto nor the Node crypto module is available.
The following elliptic curve algorithms are impacted by this issue (all in lib/deps/ecc/index.js):
exports.generateKeyPair)ECPrivateKey.prototype.toPublicKey)ECPrivateKey.prototype.sign)ECPublicKey.prototype.verify)ECPrivateKey.prototype.computeSecret)In the first three cases, the points being evaluated are generated randomly, so an attack could only arise due to a bad value being randomly selected (as noted above, with probability roughly 2^{-20}). In the latter two cases, the points being evaluated are provided from outside the library, and thus potentially by attackers.
Has the problem been patched? What versions should users upgrade to?
Since this issue is only present in the "fallback" crypto implementation, it can be avoided by ensuring that either WebCrypto or the Node crypto module is available in the JS environment where node-jose is being run.
If you have any questions or comments about this advisory:
Cisco node-jose improper validation of JWT signature
A vulnerability in the Cisco node-jose open source library before 0.11.0 could allow an unauthenticated, remote attacker to re-sign tokens using a key that is embedded within the token. The vulnerability is due to node-jose following the JSON Web Signature (JWS) standard for JSON Web Tokens (JWTs). This standard specifies that a JSON Web Key (JWK) representing a public key can be embedded within the header of a JWS. This public key is then trusted for verification. An attacker could exploit this by forging valid JWS objects by removing the original signature, adding a new public key to the header, and then signing the object using the (attacker-owned) private key associated with the public key embedded in that JWS header.
Invalid Curve Attack in node-jose
Affected versions of node-jose are vulnerable to an invalid curve attack. This allows an attacker to recover the private secret key when JWE with Key Agreement with Elliptic Curve Diffie-Hellman Ephemeral Static (ECDH-ES) is used.
Update to version 0.9.3 or later.
Prototype Pollution in lodash
Versions of lodash prior to 4.17.19 are vulnerable to Prototype Pollution. The functions pick, set, setWith, update, updateWith, and zipObjectDeep allow a malicious user to modify the prototype of Object if the property identifiers are user-supplied. Being affected by this issue requires manipulating objects based on user-provided property values or arrays.
This vulnerability causes the addition or modification of an existing property that will exist on all objects and may lead to Denial of Service or Code Execution under specific circumstances.