Vulnerability Details : 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 matching rules, gaining access to unauthorized resources.
Exploit prediction scoring system (EPSS) score for CVE-2019-9900
Probability of exploitation activity in the next 30 days: 0.45%
Percentile, the proportion of vulnerabilities that are scored at or less: ~ 75 % EPSS Score History EPSS FAQ
CVSS scores for CVE-2019-9900
| Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source |
|---|---|---|---|---|---|
|
7.5
|
HIGH | AV:N/AC:L/Au:N/C:P/I:P/A:P |
10.0
|
6.4
|
NIST |
|
6.5
|
MEDIUM | CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:L |
2.2
|
3.7
|
MITRE |
|
8.3
|
HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L |
3.9
|
3.7
|
NIST |
CWE ids for CVE-2019-9900
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The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.Assigned by: nvd@nist.gov (Primary)
References for CVE-2019-9900
-
https://access.redhat.com/errata/RHSA-2019:0741
RHSA-2019:0741 - Security Advisory - Red Hat Customer PortalThird Party Advisory
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https://groups.google.com/forum/#!topic/envoy-announce/VoHfnDqZiAM
Google GroepenThird Party Advisory
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https://github.com/envoyproxy/envoy/issues/6434
CVE-2019-9900 · Issue #6434 · envoyproxy/envoy · GitHubExploit;Issue Tracking;Third Party Advisory
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https://www.envoyproxy.io/docs/envoy/v1.9.1/intro/version_history
Version history — envoy tag-v1.9.1 documentationRelease Notes;Vendor Advisory
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https://github.com/envoyproxy/envoy/security/advisories/GHSA-x74r-f4mw-c32h
NUL characters in HTTP/1 headers allow access control bypass (CVE-2019-9900) · Advisory · envoyproxy/envoy · GitHubExploit;Mitigation;Third Party Advisory
Products affected by CVE-2019-9900
- cpe:2.3:a:redhat:openshift_service_mesh:-:*:*:*:*:*:*:*
- cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*