Is This vulnerability exploited in the wild?

No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

How severe is This vulnerability?

Low severity, with a CVSS score of 3.1, published 30 June 2020.

Which products and versions are affected?

jsrsasign (npm) SEMVER:introduced=4.0.0,fixed=8.0.13.

Is there a fix for This vulnerability?

Yes. jsrsasign (npm): upgrade to 8.0.13 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is This vulnerability attacked?

It is attacked with local access or from the adjacent network, in a software library.

Check whether you run jsrsasign (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

jsrsasign ECDSA timing attack in signature generation

Severity: low · CVSS 3.1 · Published 2020-06-30

jsrsasign is a JavaScript cryptographic library that implements ECDSA (Elliptic Curve Digital Signature Algorithm) for digital signing. A timing side-channel vulnerability named Minerva allows attackers to recover private encryption keys by measuring how long ECDSA signature generation takes, since the computation time depends on the bits of the private key value.

Technologies: jsrsasign (npm). Vendors: npm.

Quick answers

Is This vulnerability exploited in the wild?: No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.
How severe is This vulnerability?: Low severity, with a CVSS score of 3.1, published 30 June 2020.
Which products and versions are affected?: jsrsasign (npm) SEMVER:introduced=4.0.0,fixed=8.0.13.
Is there a fix for This vulnerability?: Yes. jsrsasign (npm): upgrade to 8.0.13 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is This vulnerability attacked?: It is attacked with local access or from the adjacent network, in a software library.
Am I affected?: Check whether you run jsrsasign (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

jsrsasign (npm): upgrade to 8.0.13 or later
```
npm install jsrsasign@8.0.13
```

Technical details

The vulnerability is a side-channel timing attack affecting ECDSA signature generation in jsrsasign versions 4.0.0 through 8.0.12. The root cause is that the ECPointFp.multiply() method uses a binary NAF (Non-Adjacent Form) multiplication algorithm whose execution time leaks information about the scalar (private key) bit-length and value. An attacker with access to measure signature generation timing across multiple operations can statistically recover the private key. The attack requires local or adjacent access to observe timing behavior, but does not require authentication or user interaction. The vulnerability is fixed in version 8.0.13 and later by implementing constant-time point multiplication.

Affected products

kjur jsrsasign 4.0.0 to 8.0.12

Timeline

2019-10-03: disclosed: Minerva attack reported in GitHub issue #411
2020-06-28: advisory: GHSA-g753-jx37-7xwh published
2020-06-30: patched: Fix released in jsrsasign 8.0.13

References

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