# ALBA-2020:3657: zlib bug fix and enhancement update

> Bug fixes for zlib on s390x architecture address incomplete raw stream generation and hardware acceleration issues, ensuring data integrity.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Not stated
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 8 Sep 2020

## What is ALBA-2020:3657?

ALBA-2020:3657 is a vulnerability in zlib-static, published on 8 Sep 2020. 

### Official description

The zlib packages provide a general-purpose lossless data compression
library that is used by many different programs.

Bug Fix(es) and Enhancement(s):

* AlmaLinux8.2 - zlib on s390x may produce incomplete raw (but not gzip/zlib)
streams (BZ#1860952)

* AlmaLinux8.2 - raw zlib test failed with DFLTCC_LEVEL_MASK set to 0x1ff
(BZ#1862108)

* AlmaLinux8.2 - Fix support for IBM Z hardware-accelerated deflate (zlib)
(BZ#1867876)

## Which versions are affected by ALBA-2020:3657?


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `zlib-static` | AlmaLinux:8 | All versions | 1.2.11-16.el8_2 |

## How do I fix ALBA-2020:3657?

Apply the vendor's patch.

## Is ALBA-2020:3657 being exploited?

There is no known exploitation of ALBA-2020:3657 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for ALBA-2020:3657 and fix it if it is affected.

What it is: ALBA-2020:3657 is a vulnerability in zlib-static, published on 8 Sep 2020. 
Exploitation: There is no known exploitation of ALBA-2020:3657 in the wild and no public exploit code.

Affected product: zlib-static. No package-level version data is available, so check the vendor advisory linked from the reference page.

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/ALBA-2020-3657/ (Markdown: https://insights.sbomify.com/ALBA-2020-3657/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/ALBA-2020:3657

---
From sbomify Insights: https://insights.sbomify.com/ALBA-2020-3657/
Summaries are generated and may contain mistakes; the official description above is the record.