Is CVE-2021-30246 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2021-30246 being exploited in the wild.

How severe is CVE-2021-30246?

Low severity, with a CVSS score of 3.1, published 16 April 2021.

Which products and versions are affected?

jsrsasign (npm) SEMVER:introduced=0,fixed=10.2.0.

Is there a fix for CVE-2021-30246?

Yes. jsrsasign (npm): upgrade to 10.2.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2021-30246 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2021-30246?

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.

CVE-2021-30246: kjur jsrsasign RSA signature validation bypass in PKCS#1 v1.5 padding

CVE-2021-30246 · Severity: low · CVSS 3.1 · Published 2021-04-16

The jsrsasign library, a popular JavaScript tool for cryptography and digital signatures, contains a vulnerability in how it validates RSA signatures. This flaw could allow an attacker to provide a specially crafted signature that is incorrectly accepted as valid, potentially leading to unauthorized access or the bypass of security checks. While the library is widely used for web security and tokens, creating a successful exploit is considered difficult in practice.

Technologies: jsrsasign (npm). Vendors: npm.

Quick answers

Is CVE-2021-30246 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2021-30246 being exploited in the wild.
How severe is CVE-2021-30246?: Low severity, with a CVSS score of 3.1, published 16 April 2021.
Which products and versions are affected?: jsrsasign (npm) SEMVER:introduced=0,fixed=10.2.0.
Is there a fix for CVE-2021-30246?: Yes. jsrsasign (npm): upgrade to 10.2.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2021-30246 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2021-30246?: 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 10.2.0 or later
```
npm install jsrsasign@10.2.0
```

Technical details

A vulnerability exists in jsrsasign versions prior to 10.2.0 where the RSA signature validation (RSASSA-PKCS1-v1_5) fails to strictly verify the length and structure of PKCS#1.5 padding. Specifically, the library does not sufficiently check that the decoded signature byte length matches the RSA key length, and it is overly lenient when parsing the block type and padding bytes (expecting 0x0001 followed by 0xFF padding). An attacker could potentially craft a malleable encoded message that bypasses signature verification. However, a practical attack remains difficult as it still requires finding hash collisions. The issue is addressed in version 10.2.0.

Affected products

kjur jsrsasign < 10.2.0

Identifiers

CVE-2021-30246
GHSA-27fj-mc8w-j9wg

Timeline

2021-04-07: advisory: NVD published CVE-2021-30246
2021-04-13: patched: Version 10.2.0 released to fix the vulnerability
2021-04-16: disclosed: GitHub Security Advisory published

References

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