# CVE-2022-25898: Improper Verification of Cryptographic Signature

> Attackers can bypass JWS or JWT signature verification using specially crafted non-Base64URL characters, allowing unauthorized access.

- **Severity:** High 7.7 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:H/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 1 Jul 2022
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-3fvg-4v2m-98jf

## What is CVE-2022-25898?

CVE-2022-25898 is a high-severity vulnerability in jsrsasign, published on 1 Jul 2022. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

The package jsrsasign before 10.5.25 are vulnerable to Improper Verification of Cryptographic Signature when JWS or JWT signature with non Base64URL encoding special characters or number escaped characters may be validated as valid by mistake. Workaround: Validate JWS or JWT signature if it has Base64URL and dot safe string before executing JWS.verify() or JWS.verifyJWT() method.

Weakness: CWE-347 (Improper Verification of Cryptographic Signature)

## Which versions are affected by CVE-2022-25898?

2 open source packages ship an affected version, including jsrsasign. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `jsrsasign` | npm | From 4.8.0 | 10.5.25 |
| `jsrsasign` | npm | From 4.8.0 | 10.5.25 |

Products: Kjur Jsrsasign.

## How do I fix CVE-2022-25898?

Upgrade jsrsasign to 10.5.25 or later.

## Is CVE-2022-25898 being exploited?

There is no known exploitation of CVE-2022-25898 in the wild and no public exploit code.

## Other vulnerabilities in jsrsasign

- [CVE-2020-14967](https://insights.sbomify.com/CVE-2020-14967/): RSA PKCS#1 decryption vulnerability with prepending zeros in jsrsasign (critical 9.8)
- [CVE-2020-14968](https://insights.sbomify.com/CVE-2020-14968/): RSA-PSS signature validation vulnerability by prepending zeros in jsrsasign (critical 9.8)
- [CVE-2026-4601](https://insights.sbomify.com/CVE-2026-4601/): jsrsasign: Missing cryptographic validation during DSA signing enables private key extraction (critical 9.4)
- [CVE-2026-4599](https://insights.sbomify.com/CVE-2026-4599/): jsrsasign: Incomplete Comparison Allows DSA Private Key Recovery via Biased Nonce Generation (critical 9.3)
- [CVE-2026-4600](https://insights.sbomify.com/CVE-2026-4600/): jsrsasign: DSA signatures or X.509 certificates can be forged via DSA domain-parameter validation in KJUR.crypto.DSA.setPublic (critical 9.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-25898 and fix it if it is affected.

What it is: CVE-2022-25898 is a high-severity vulnerability in jsrsasign, published on 1 Jul 2022. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2022-25898 in the wild and no public exploit code.

Affected packages and fixed versions:
- jsrsasign (npm): affected from 4.8.0; fixed in 10.5.25
- jsrsasign (npm): affected from 4.8.0; fixed in 10.5.25

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2022-25898/ (Markdown: https://insights.sbomify.com/CVE-2022-25898/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-25898
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-25898
- OSV: https://osv.dev/vulnerability/CVE-2022-25898

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-25898/
Summaries are generated and may contain mistakes; the official description above is the record.