CVE-2019-8400 — ORY Hydra before v1

ORY Hydra before v1.0.0-rc.3+oryOS.9 has Reflected XSS via the oauth2/fallbacks/error error_hint parameter.

01What is this vulnerability?

ORY Hydra before v1.0.0-rc.3+oryOS.9 has Reflected XSS via the oauth2/fallbacks/error error_hint parameter.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2019-02-17T06:00:00.000Z
• Last modified: 2024-08-04T21:17:31.580Z

09References

• drive.google.com — https://drive.google.com/file/d/1-25expUYVfK6vsiCmEabUCuelOP7aUDj/view?usp=drive…
• www.youtube.com — https://www.youtube.com/watch?v=RIyZLeKEC8E
• github.com — https://github.com/ory/hydra/blob/master/CHANGELOG.md#v100-rc3oryos9-2018-12-06
• hackerone.com — https://hackerone.com/reports/456333
• github.com — https://github.com/ory/hydra/commit/9b5bbd48a72096930af08402c5e07fce7dd770f3