# CVE-2020-1957: Improper Authentication in Apache Shiro

> Attackers can bypass authentication in Apache Shiro when integrated with Spring dynamic controllers via specially crafted requests.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Mar 2020
- **Updated:** 4 Aug 2024
- **Also known as:** DEBIAN-CVE-2020-1957, DLA-2181-1, GHSA-26gr-cvq3-qxgf, UBUNTU-CVE-2020-1957

## What is CVE-2020-1957?

CVE-2020-1957 is a critical authentication bypass vulnerability in Debian Debian Linux, published on 25 Mar 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Apache Shiro before 1.5.2, when using Apache Shiro with Spring dynamic controllers, a specially crafted request may cause an authentication bypass.

## Which versions are affected by CVE-2020-1957?

2 open source packages ship an affected version, including org.apache.shiro:shiro-core. It affects 2 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.apache.shiro:shiro-core` | Maven | All versions | 1.5.2 |
| `org.apache.shiro:shiro-core` | Maven | All versions | 1.5.2 |

Products: Apache Shiro, Debian Debian Linux.

## How do I fix CVE-2020-1957?

Upgrade org.apache.shiro:shiro-core to 1.5.2 or later.

## Is CVE-2020-1957 being exploited?

There is no known exploitation of CVE-2020-1957 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2023-34478](https://insights.sbomify.com/CVE-2023-34478/): Path Traversal in Apache Shiro (critical 9.8)
- [CVE-2022-40664](https://insights.sbomify.com/CVE-2022-40664/): Authentication Bypass Vulnerability in Shiro when forwarding or including via RequestDispatcher (critical 9.8)
- [CVE-2022-32532](https://insights.sbomify.com/CVE-2022-32532/): Authentication Bypass Vulnerability (critical 9.8)
- [CVE-2021-41303](https://insights.sbomify.com/CVE-2021-41303/): Apache Shiro vulnerable to a specially crafted HTTP request causing an authentication bypass (critical 9.8)
- [CVE-2020-17523](https://insights.sbomify.com/CVE-2020-17523/): Authentication bypass in Apache Shiro (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-1957 and fix it if it is affected.

What it is: CVE-2020-1957 is a critical authentication bypass vulnerability in Debian Debian Linux, published on 25 Mar 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-1957 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.apache.shiro:shiro-core (Maven): affected all versions; fixed in 1.5.2
- org.apache.shiro:shiro-core (Maven): affected all versions; fixed in 1.5.2

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-2020-1957/ (Markdown: https://insights.sbomify.com/CVE-2020-1957/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-1957
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-1957
- OSV: https://osv.dev/vulnerability/CVE-2020-1957

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-1957/
Summaries are generated and may contain mistakes; the official description above is the record.