bottle HTTP Request smuggling

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.1 · CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2020-28473: 1.79% estimated exploitation activity in the next 30 days; percentile 78.35 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

The package bottle before 0.12.19 are vulnerable to Web Cache Poisoning by using a vector called parameter cloaking. When the attacker can separate query parameters using a semicolon (;), they can cause a difference in the interpretation of the request between the proxy (running with default configuration) and the server. This can result in malicious requests being cached as completely safe ones, as the proxy would usually not see the semicolon as a separator, and therefore would not include it in a cache key of an unkeyed parameter.

Published by the source

7 Apr 2021, 21:05 UTC

Last modified by the source

13 Sep 2024, 14:45 UTC

Source last checked

26 Oct 2026, 13:16 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-qhx9-7hx7-cp4r

2. Revision 2 · amended · 25 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-qhx9-7hx7-cp4r

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# Patch Next advisory brief: CVE-2020-28473

Advisory: bottle HTTP Request smuggling
IDs: CVE-2020-28473, GHSA-qhx9-7hx7-cp4r
Record: https://patchnext.com/advisories/cve-2020-28473 (revision 3, source checked 26 Oct 2026, 13:16 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: bottle 0.12.19. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI bottle: affected < 0.12.19; fixed in 0.12.19

## Suggested inspection (read-only)
- `python -m pip show bottle`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on bottle.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-qhx9-7hx7-cp4r (OSV record GHSA-qhx9-7hx7-cp4r lists affected ranges: PyPI bottle >=0 <0.12.19 (fixed))
- Verified: https://github.com/advisories/GHSA-qhx9-7hx7-cp4r (GitHub-reviewed advisory GHSA-qhx9-7hx7-cp4r lists affected ranges: PyPI bottle >=0 <0.12.19)

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