# CVE-2016-9843: Other in n/a

> A potential issue in the zlib library's big-endian CRC calculation might allow context-dependent attackers to cause unspecified impacts.

- **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:** 23 May 2017
- **Updated:** 6 Aug 2024
- **Also known as:** ALPINE-CVE-2016-9843, AZL-44352, AZL-45366, CLSA-2026-1772177379, CLSA-2026-1772213586, CLSA-2026-1772213835, CLSA-2026-1772454796, CLSA-2026-1782981445, DEBIAN-CVE-2016-9843, GHSA-q27x-567x-5347, MINI-98rr-4gcw-5558, PSF-2017-5, UBUNTU-CVE-2016-9843, USN-7959-1, openSUSE-SU-2024:10283-1

## What is CVE-2016-9843?

CVE-2016-9843 is a critical vulnerability in Apple Iphone Os, published on 23 May 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The crc32_big function in crc32.c in zlib 1.2.8 might allow context-dependent attackers to have unspecified impact via vectors involving big-endian CRC calculation.

## Which versions are affected by CVE-2016-9843?

It affects 24 products.


Products: Apple Iphone Os, Apple Mac Os X, Apple Tvos, Apple Watchos, Canonical Ubuntu Linux, Debian Debian Linux, Mariadb Mariadb, Netapp Active Iq Unified Manager, Netapp Oncommand Insight, Netapp Oncommand Workflow Automation, Netapp Snapcenter, Nodejs Node.js, Opensuse Leap, Opensuse Opensuse, Oracle Database Server, Oracle Jdk, Oracle Jre, Oracle Mysql, Redhat Enterprise Linux Desktop, Redhat Enterprise Linux Eus and 4 more.

## How do I fix CVE-2016-9843?

Upgrade to a fixed version.

## Is CVE-2016-9843 being exploited?

There is no known exploitation of CVE-2016-9843 in the wild and no public exploit code.

## Other vulnerabilities in Apple Iphone Os

- [CVE-2021-30666](https://insights.sbomify.com/CVE-2021-30666/): Apple iOS WebKit Buffer Overflow (high 8.8, exploited in the wild)
- [CVE-2021-30761](https://insights.sbomify.com/CVE-2021-30761/): Apple iOS WebKit Memory Corruption (high 8.8, exploited in the wild)
- [CVE-2021-30762](https://insights.sbomify.com/CVE-2021-30762/): Apple iOS WebKit Use-After-Free (high 8.8, exploited in the wild)
- [CVE-2016-4657](https://insights.sbomify.com/CVE-2016-4657/): Apple iOS Webkit Memory Corruption (high 8.8, exploited in the wild)
- [CVE-2019-7286](https://insights.sbomify.com/CVE-2019-7286/): Apple Multiple Products Memory Corruption (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-9843 and fix it if it is affected.

What it is: CVE-2016-9843 is a critical vulnerability in Apple Iphone Os, published on 23 May 2017. 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-2016-9843 in the wild and no public exploit code.

Affected product: Apple Iphone Os. 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/CVE-2016-9843/ (Markdown: https://insights.sbomify.com/CVE-2016-9843/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-9843
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-9843
- OSV: https://osv.dev/vulnerability/CVE-2016-9843

---
From sbomify Insights: https://insights.sbomify.com/CVE-2016-9843/
Summaries are generated and may contain mistakes; the official description above is the record.