// For flags

CVE-2019-9900

istio/envoy: Authorization bypass via null characters injection in HTTP/1.x

Severity Score

8.3
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

2
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

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 matching rules, gaining access to unauthorized resources.

Al analizar los valores de encabezado HTTP/1.x, Envoy versión 1.9.0 y anteriores, no rechazan los caracteres de cero incrustados (NUL, ASCII 0x0). Esto permite que los atacantes remotos que crean valores de encabezado que contienen caracteres NUL insertados puedan omitir potencialmente las reglas de coincidencia de encabezado, logrando el acceso a recursos no autorizados.

A flaw was found in Envoy version 1.9.0 and older, where Envoy does not reject embedded zero characters (NUL, ASCII 0x0) when processing HTTP/1.x header values. This flaw allows remote attackers crafting header values containing embedded NUL characters to potentially bypass header matching rules, gaining access to unauthorized resources.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
Low
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
Low
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
Low
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2019-03-21 CVE Reserved
  • 2019-04-11 CVE Published
  • 2024-08-04 CVE Updated
  • 2024-08-04 First Exploit
  • 2024-09-15 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
CWE
  • CWE-20: Improper Input Validation
  • CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Envoyproxy
Search vendor "Envoyproxy"
 Envoy
Search vendor "Envoyproxy" for product "Envoy"
 <= 1.9.0
Search vendor "Envoyproxy" for product "Envoy" and version " <= 1.9.0"
-
Affected
Redhat
Search vendor "Redhat"
 Openshift Service Mesh
Search vendor "Redhat" for product "Openshift Service Mesh"
--
Affected