CVSS3
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
AI Score
Confidence
High
EPSS
Percentile
73.7%
Envoy is a cloud-native edge/middle/service proxy. Envoy does not decode escaped slash sequences %2F
and %5C
in HTTP URL paths in versions 1.18.2 and before. A remote attacker may craft a path with escaped slashes, e.g. /something%2F..%2Fadmin
, to bypass access control, e.g. a block on /admin
. A backend server could then decode slash sequences and normalize path and provide an attacker access beyond the scope provided for by the access control policy. ### Impact Escalation of Privileges when using RBAC or JWT filters with enforcement based on URL path. Users with back end servers that interpret %2F
and /
and %5C
and \
interchangeably are impacted. ### Attack Vector URL paths containing escaped slash characters delivered by untrusted client. Patches in versions 1.18.3, 1.17.3, 1.16.4, 1.15.5 contain new path normalization option to decode escaped slash characters. As a workaround, if back end servers treat %2F
and /
and %5C
and \
interchangeably and a URL path based access control is configured, one may reconfigure the back end server to not treat %2F
and /
and %5C
and \
interchangeably.
[
{
"product": "envoy",
"vendor": "envoyproxy",
"versions": [
{
"status": "affected",
"version": "<= 1.18.2"
}
]
}
]
CVSS3
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
AI Score
Confidence
High
EPSS
Percentile
73.7%