High, CVSS 7.5npmAmendedPublished
browserify-sign upper bound check issue in dsaVerify leads to a signature forgery attack
CVE-2023-46234 · GHSA-x9w5-v3q2-3rhw
- Affected
- npm browserify-sign >= 2.6.0, <= 4.2.1
- Fixed in
- 4.2.2· Vendor fix available
- Issue
- An upper bound check issue in dsaVerify function allows an attacker to construct signatures that can be successfully verified by any public key, thus leading to a signature forgery attack. Details In dsaVerify function, it checks whether the value of the signature is legal by calling function checkValue, namely, whether r and s are both in the interval [1, q - 1]. However, the second line of the checkValue function wrongly checks the upper bound of the passed parameters, since the value of b.cmp(q) can only be 0, 1 and -1, and it can never be greater than q. In this way, although the values of s cannot be 0, an attacker can achieve the same effect as zero by setting its value to q, and then send (r, s) = (1, q) to pass the verification of any public key. Impact All places in this project that involve DSA verification of user-input signatures will be affected by this vulnerability. Fix PR: Since the temporary private fork was deleted, here's a webarchive of the PR discussion…
Recommended action: Upgrade to 4.2.2 or later, then redeploy and verify.A vendor fix does not resolve your finding until you verify it in your own systems.