# CVE-2023-28119: crewjam/saml vulnerable to Denial Of Service Via Deflate Decompression Bomb

> An attacker can crash the application by sending large compressed SAML requests, causing a denial of service via resource exhaustion.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:** 22 Mar 2023
- **Updated:** 25 Feb 2025
- **Also known as:** GHSA-5mqj-xc49-246p, GO-2023-1664, UBUNTU-CVE-2023-28119

## What is CVE-2023-28119?

CVE-2023-28119 is a high-severity denial of service vulnerability in crewjam saml, published on 22 Mar 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The crewjam/saml go library contains a partial implementation of the SAML standard in golang. Prior to version 0.4.13, the package's use of `flate.NewReader` does not limit the size of the input. The user can pass more than 1 MB of data in the HTTP request to the processing functions, which will be decompressed server-side using the Deflate algorithm. Therefore, after repeating the same request multiple times, it is possible to achieve a reliable crash since the operating system kills the process. This issue is patched in version 0.4.13.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2023-28119?

3 open source packages ship an affected version, including github.com/crewjam/saml. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/crewjam/saml` | Go | All versions | 0.4.13 |
| `github.com/crewjam/saml` | Go | All versions | 0.4.13 |
| `github.com/crewjam/saml` | Go | All versions | 0.4.13 |

Products: Saml Project Saml.

## How do I fix CVE-2023-28119?

Upgrade github.com/crewjam/saml to 0.4.13 or later.

## Is CVE-2023-28119 being exploited?

There is no known exploitation of CVE-2023-28119 in the wild and no public exploit code.

## Other vulnerabilities in crewjam saml

- [CVE-2022-41912](https://insights.sbomify.com/CVE-2022-41912/): crewjam/saml go library is vulnerable to signature bypass via multiple Assertion elements (critical 9.1)
- [CVE-2023-45683](https://insights.sbomify.com/CVE-2023-45683/): Cross site scripting via missing binding syntax validation In ACS location in github.com/crewjam/saml (high 7.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-28119 and fix it if it is affected.

What it is: CVE-2023-28119 is a high-severity denial of service vulnerability in crewjam saml, published on 22 Mar 2023. 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-2023-28119 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/crewjam/saml (Go): affected all versions; fixed in 0.4.13
- github.com/crewjam/saml (Go): affected all versions; fixed in 0.4.13
- github.com/crewjam/saml (Go): affected all versions; fixed in 0.4.13

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-2023-28119/ (Markdown: https://insights.sbomify.com/CVE-2023-28119/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-28119
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-28119
- OSV: https://osv.dev/vulnerability/CVE-2023-28119

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-28119/
Summaries are generated and may contain mistakes; the official description above is the record.