Vulnerability in Envoyproxy Envoy

CVE-2019-9900

When parsing HTTP/1.x header values, Envoy 1.9.0 and before does not reject embedded zero characters (NUL, ASCII 0x0). This allows remote attackers crafting header values containing embedded NUL characters to potentially bypass header matc…

EPSS: 0.037 (88.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

  • cve@mitre.org (x_refsource_REDHAT, vendor-advisory, Third Party Advisory)
  • cve@mitre.org (x_refsource_CONFIRM, Release Notes, Vendor Advisory)
  • cve@mitre.org (x_refsource_CONFIRM, Exploit, Third Party Advisory, Issue Tracking)
  • cve@mitre.org (x_refsource_CONFIRM)
  • cve@mitre.org (x_refsource_CONFIRM, Exploit, Third Party Advisory, Mitigation)

Frequently asked questions

What is CVE-2019-9900?
CVE-2019-9900 is a high-severity vulnerability in Envoyproxy Envoy, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 8.3/10. Published 2019-04-25.
How severe is CVE-2019-9900?
High severity. CVSS v3 base score is 8.3 out of 10.
Is CVE-2019-9900 known to be exploited?
3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.