# CVE-2020-5407: Signature Wrapping Vulnerability with spring-security-saml2-service-provider

> Attackers can bypass SAML authentication by appending arbitrary assertions to valid responses, allowing unauthorized access in applications using Spring Security SAML.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 13 May 2020
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-48rw-j489-928m

## What is CVE-2020-5407?

CVE-2020-5407 is a high-severity authentication bypass vulnerability in Spring Security, published on 13 May 2020. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Spring Security versions 5.2.x prior to 5.2.4 and 5.3.x prior to 5.3.2 contain a signature wrapping vulnerability during SAML response validation. When using the spring-security-saml2-service-provider component, a malicious user can carefully modify an otherwise valid SAML response and append an arbitrary assertion that Spring Security will accept as valid.

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

## Which versions are affected by CVE-2020-5407?

4 open source packages ship an affected version, including org.springframework.security:spring-security-core. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.springframework.security:spring-security-core` | Maven | From 5.2.0 | 5.2.4 |
| `org.springframework.security:spring-security-core` | Maven | From 5.2.0 | 5.2.4 |
| `org.springframework.security:spring-security-core` | Maven | From 5.3.0 | 5.3.2 |
| `org.springframework.security:spring-security-core` | Maven | From 5.3.0 | 5.3.2 |

Products: Pivotal Software Spring Security.

## How do I fix CVE-2020-5407?

Upgrade org.springframework.security:spring-security-core to a fixed version for your release line: 5.2.4 or 5.3.2.

## Is CVE-2020-5407 being exploited?

There is no known exploitation of CVE-2020-5407 in the wild and no public exploit code.

## Other vulnerabilities in Spring Security

- [CVE-2020-5408](https://insights.sbomify.com/CVE-2020-5408/): Dictionary attack with Spring Security queryable text encryptor (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-5407 and fix it if it is affected.

What it is: CVE-2020-5407 is a high-severity authentication bypass vulnerability in Spring Security, published on 13 May 2020. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-5407 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.springframework.security:spring-security-core (Maven): affected from 5.2.0; fixed in 5.2.4
- org.springframework.security:spring-security-core (Maven): affected from 5.2.0; fixed in 5.2.4
- org.springframework.security:spring-security-core (Maven): affected from 5.3.0; fixed in 5.3.2
- org.springframework.security:spring-security-core (Maven): affected from 5.3.0; fixed in 5.3.2

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-2020-5407/ (Markdown: https://insights.sbomify.com/CVE-2020-5407/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-5407
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-5407
- OSV: https://osv.dev/vulnerability/CVE-2020-5407

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-5407/
Summaries are generated and may contain mistakes; the official description above is the record.