High
Security advisory
Envoy is an open source edge and service proxy, designed for cloud-native applications. In affected versions a crafted request crashes Envoy when a CONNECT request is sent to JWT filter configured with regex match. This provides a denial of service attack vector. The only workaround is to not use regex in the JWT filter. Users are advised to upgrade.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2021-43824
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 13:02 UTC · Revision 1
Source evidence
Envoy is an open source edge and service proxy, designed for cloud-native applications. In affected versions a crafted request crashes Envoy when a CONNECT request is sent to JWT filter configured with regex match. This provides a denial of service attack vector. The only workaround is to not use regex in the JWT filter. Users are advised to upgrade.
osv:CVE-2021-43824
Complete source record
{
"id": "0f94defad19806ccd698f00cccd787b89fe81b69717e8496fde6d8b713e86710",
"url": "https://osv.dev/vulnerability/CVE-2021-43824",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2021-43824",
"summary": "Envoy is an open source edge and service proxy, designed for cloud-native applications. In affected versions a crafted request crashes Envoy when a CONNECT request is sent to JWT filter configured with regex match. This provides a denial of service attack vector. The only workaround is to not use regex in the JWT filter. Users are advised to upgrade.",
"evidence": "osv:CVE-2021-43824",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2021-43824",
"aliases": [
"BIT-envoy-2021-43824",
"CVE-2021-43824",
"GHSA-vj5m-rch8-5r2p"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/envoyproxy/envoy",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "a79ca225f1ed924b855dff8a26bd7f7cdb84e694"
},
{
"introduced": "68fe53a889416fd8570506232052b06f5a531541"
},
{
"fixed": "a17cdcdfad24de101e95716b77549ba689824f25"
},
{
"introduced": "96701cb24611b0f3aac1cc0dd8bf8589fbdf8e9e"
},
{
"fixed": "4aaf9593152c6996b9da384c8918e9ad4f0abd4d"
},
{
"introduced": "a9d72603c68da3a10a1c0d021d01c7877e6f2a30"
},
{
"fixed": "af50070ee60866874b0a9383daf9364e884ded22"
},
{
"fixed": "9371333230b1a6e1be2eccf4868771e11af6253a"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "1.18.6"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "1.19.0"
},
{
"fixed": "1.19.3"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "1.20.0"
},
{
"fixed": "1.20.2"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "1.21.0"
},
{
"fixed": "1.21.1"
}
],
"source": "CPE_RANGE"
},
{
"range": [
{
"fixed": "9371333230b1a6e1be2eccf4868771e11af6253a"
}
],
"source": "REFERENCES_COMMIT"
}
]
}
}
],
"versions": [
"v1.21.0",
"v1.20.1",
"v1.20.0",
"v1.18.4",
"v1.19.1",
"v1.19.0",
"v1.18.3",
"v1.18.2",
"v1.18.1",
"v1.18.0",
"v1.17.0",
"v1.16.0",
"v1.15.0",
"v1.14.0",
"v1.13.0",
"v1.12.0",
"v1.11.0",
"v1.10.0",
"v1.9.0",
"v1.8.0",
"v1.7.0",
"v1.6.0",
"v1.5.0",
"v1.4.0",
"v1.3.0",
"v1.2.0",
"v1.1.0",
"v1.0.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-43824.json",
"vanir_signatures": [
{
"id": "CVE-2021-43824-097fed22",
"digest": {
"threshold": 0.9,
"line_hashes": [
"245673340480709380475607110780385137708",
"285494569074532567258474565032572094364",
"121492910522987967398570563042373873103",
"208903825150298770882316003860954195851"
]
},
"source": "https://github.com/envoyproxy/envoy/commit/af50070ee60866874b0a9383daf9364e884ded22",
"target": {
"file": "source/common/tcp_proxy/tcp_proxy.h"
},
"deprecated": false,
"signature_type": "Line",
"signature_version": "v1"
},
{
"id": "CVE-2021-43824-0e4fc27e",
"digest": {
"length": 711,
"function_hash": "63191530169222520921233896458439701262"
},
"source": "https://github.com/envoyproxy/envoy/commit/a79ca225f1ed924b855dff8a26bd7f7cdb84e694",
"target": {
"file": "source/common/tcp_proxy/tcp_proxy.cc",
"function": "Filter::onUpstreamEvent"
},
"deprecated": false,
"signature_type": "Function",
"signature_version": "v1"
},
{
"id": "CVE-2021-43824-21f82a03",
"digest": {
"threshold": 0.9,
"line_hashes": [
"16695513628882731710386236080108344740",
"226065387100708587604550551532432243880",
"16435745593053750970339365835642838940",
"290690702275778456420641259607659362098"
]
},
"source": "https://github.com/envoyproxy/envoy/commit/9371333230b1a6e1be2eccf4868771e11af6253a",
"target": {
"file": "source/extensions/filters/http/jwt_authn/matcher.cc"
},
"deprecated": false,
"signature_type": "Line",
"signature_version": "v1"
},
{
"id": "CVE-2021-43824-25d456d2",
"digest": {
"threshold": 0.9,
"line_hashes": [
"146243477446113422387021212725253250778",
"38867459780981627133568037950540228786",
"247042036583305394760031334831783811398",
"325013980647195303750429821852338176203",
"190222441294940987692714025372522320194",
"233481120278761949454860284316900076892",
"33182693539138785849824461743826464632",
"238411867963402661331142337279192022640"
]
},
"source": "https://github.com/envoyproxy/envoy/commit/a17cdcdfad24de101e95716b77549ba689824f25",
"target": {
"file": "source/common/tcp_proxy/tcp_proxy.cc"
},
"deprecated": false,
"signature_type": "Line",
"signature_version": "v1"
},
{
"id": "CVE-2021-43824-3fe0ae84",
"digest": {
"length": 648,
"function_hash": "243442652017391788382200176589855195754"
},
"source": "https://github.com/envoyproxy/envoy/commit/a79ca225f1ed924b855dff8a26bd7f7cdb84e694",
"target": {
"file": "source/common/tcp_proxy/tcp_proxy.cc",
"function": "Filter::onDownstreamEvent"
},
"deprecated": false,
"signature_type": "Function",
"signature_version": "v1"
},
{
"id": "CVE-2021-43824-49af67d3",
"digest": {
"threshold": 0.9,
"line_hashes": [
"48555961344162091530114484247512887348",
"262502622330308196055685632396206527810",
"44051101608002913249948422506083140770"
]
},
"source": "https://github.com/envoyproxy/envoy/commit/a79ca225f1ed924b855dff8a26bd7f7cdb84e694",
"target": {
"file": "test/integration/tcp_tunneling_integration_test.cc"
},
"deprecated": false,
"signature_type": "Line",
"signature_version": "v1"
},
{
"id": "CVE-2021-43824-4f2f527a",
"digest": {
"threshold": 0.9,
"line_hashes": [
"48555961344162091530114484247512887348",
"262502622330308196055685632396206527810",
"44051101608002913249948422506083140770"
]
},
"source": "https://github.com/envoyproxy/envoy/commit/a17cdcdfad24de101e95716b77549ba689824f25",
"target": {
"file": "test/integration/tcp_tunneling_integration_test.cc"
},
"deprecated": false,
"signature_type": "Line",
"signature_version": "v1"
},
{
"id": "CVE-2021-43824-750e7fbb",
"digest": {
"length": 338,
"function_hash": "43013079311173114698727080572662162328"
},
"source": "https://github.com/envoyproxy/envoy/commit/4aaf9593152c6996b9da384c8918e9ad4f0abd4d",
"target": {
"file": "source/common/conn_pool/conn_pool_base.cc",
"function": "ConnPoolImplBase::checkForIdleAndCloseIdleConnsIfDraining"
},
"deprecated": false,
"signature_type": "Function",
"signature_version": "v1"
},
{
"id": "CVE-2021-43824-75516c6f",
"digest": {
"threshold": 0.9,
"line_hashes": [
"238363169343804913942300291017684487943",
"281075802092293195505541183629950851527",
"190309091056183134939303314630437286332",
"1336839216182560585869212455485126136",
"91854374677920975889051724337189261314",
"176073550574850004587196271703191506168",
"54303611712421497849276770032572170236",
"89596254872871249889385232134194772639",
"232868586170569298338666905475474416875",
"68418232771506422252069681807775341343"
]
},
"source": "https://github.com/envoyproxy/envoy/commit/4aaf9593152c6996b9da384c8918e9ad4f0abd4d",
"target": {
"file": "source/common/conn_pool/conn_pool_base.h"
},
"deprecated": false,
"signature_type": "Line",
"signature_version": "v1"
},
{
"id": "CVE-2021-43824-8a3c3605",
"digest": {
"length": 711,
"function_hash": "63191530169222520921233896458439701262"
},
"source": "https://github.com/envoyproxy/envoy/commit/a17cdcdfad24de101e95716b77549ba689824f25",
"target": {
"file": "source/common/tcp_proxy/tcp_proxy.cc",
"function": "Filter::onUpstreamEvent"
},
"deprecated": false,
"signature_type": "Function",
"signature_version": "v1"
},
{
"id": "CVE-2021-43824-9c39651a",
"digest": {
"threshold": 0.9,
"line_hashes": [
"222375982320279527150068471158201686244",
"165738277750233846199418982723160704713",
"44051101608002913249948422506083140770"
]
},
"source": "https://github.com/envoyproxy/envoy/commit/af50070ee60866874b0a9383daf9364e884ded22",
"target": {
"file": "test/integration/tcp_tunneling_integration_test.cc"
},
"deprecated": false,
"signature_type": "Line",
"signature_version": "v1"
},
{
"id": "CVE-2021-43824-a6789e61",
"digest": {
"length": 808,
"function_hash": "296559161755360112084384558440136934044"
},
"source": "https://github.com/envoyproxy/envoy/commit/af50070ee60866874b0a9383daf9364e884ded22",
"target": {
"file": "source/common/tcp_proxy/tcp_proxy.cc",
"function": "Filter::onDownstreamEvent"
},
"deprecated": false,
"signature_type": "Function",
"signature_version": "v1"
},
{
"id": "CVE-2021-43824-abeb66c1",
"digest": {
"length": 648,
"function_hash": "243442652017391788382200176589855195754"
},
"source": "https://github.com/envoyproxy/envoy/commit/a17cdcdfad24de101e95716b77549ba689824f25",
"target": {
"file": "source/common/tcp_proxy/tcp_proxy.cc",
"function": "Filter::onDownstreamEvent"
},
"deprecated": false,
"signature_type": "Function",
"signature_version": "v1"
},
{
"id": "CVE-2021-43824-b538155e",
"digest": {
"threshold": 0.9,
"line_hashes": [
"115441571730810549079652967827902341184",
"60438389137165276459256521079623731500",
"325439369076572620572492726448389973123"
]
},
"source": "https://github.com/envoyproxy/envoy/commit/9371333230b1a6e1be2eccf4868771e11af6253a",
"target": {
"file": "test/extensions/filters/http/jwt_authn/test_common.h"
},
"deprecated": false,
"signature_type": "Line",
"signature_version": "v1"
},
{
"id": "CVE-2021-43824-bf50e605",
"digest": {
"threshold": 0.9,
"line_hashes": [
"97652407307682118633090827808836069896",
"202222073443799289957911450767890213833",
"115564202354952612799820744008677299818",
"100865938374520508671052066897428637482",
"266358857140130331037141171435995735386",
"241277250285489246241581928533925069698",
"112864798336767260895615422020255373801",
"326344252156913283305823248376635974319",
"149501076714298581724217944116072240117",
"20851967513280832025446682514306651511",
"101660301215173511645125806388931558046",
"161983258376373368998625288716073445864",
"125013157627477663648794220335175813129",
"114297756736507093046297363714182913184",
"326342629182717535494243166437244508087",
"129503348076797258550455082149053172774",
"6063454819406071701935832397149074681",
"25450544109902264946434894665349483615",
"14209541420216802153449926603071335280",
"28083104488430351869423149520385632380",
"27329837804645812211356628610675816305"
]
},
"source": "https://github.com/envoyproxy/envoy/commit/4aaf9593152c6996b9da384c8918e9ad4f0abd4d",
"target": {
"file": "test/integration/cds_integration_test.cc"
},
"deprecated": false,
"signature_type": "Line",
"signature_version": "v1"
},
{
"id": "CVE-2021-43824-c143ebbc",
"digest": {
"threshold": 0.9,
"line_hashes": [
"245673340480709380475607110780385137708",
"285494569074532567258474565032572094364",
"189982742750395040949615227195286815818",
"260972069293896305361331050164952443697"
]
},
"source": "https://github.com/envoyproxy/envoy/commit/a17cdcdfad24de101e95716b77549ba689824f25",
"target": {
"file": "source/common/tcp_proxy/tcp_proxy.h"
},
"deprecated": false,
"signature_type": "Line",
"signature_version": "v1"
},
{
"id": "CVE-2021-43824-c4824ee2",
"digest": {
"threshold": 0.9,
"line_hashes": [
"146243477446113422387021212725253250778",
"38867459780981627133568037950540228786",
"247042036583305394760031334831783811398",
"325013980647195303750429821852338176203",
"190222441294940987692714025372522320194",
"233481120278761949454860284316900076892",
"33182693539138785849824461743826464632",
"238411867963402661331142337279192022640"
]
},
"source": "https://github.com/envoyproxy/envoy/commit/a79ca225f1ed924b855dff8a26bd7f7cdb84e694",
"target": {
"file": "source/common/tcp_proxy/tcp_proxy.cc"
},
"deprecated": false,
"signature_type": "Line",
"signature_version": "v1"
},
{
"id": "CVE-2021-43824-ce5c4e8e",
"digest": {
"threshold": 0.9,
"line_hashes": [
"150676539833679190158940891882333303963",
"27409818851555323095073296906901027733",
"55324179392422643085196396072729602785"
]
},
"source": "https://github.com/envoyproxy/envoy/commit/4aaf9593152c6996b9da384c8918e9ad4f0abd4d",
"target": {
"file": "test/config/utility.h"
},
"deprecated": false,
"signature_type": "Line",
"signature_version": "v1"
},
{
"id": "CVE-2021-43824-cf3745ce",
"digest": {
"threshold": 0.9,
"line_hashes": [
"26722413740939448104101388019871754100",
"285494569074532567258474565032572094364",
"189982742750395040949615227195286815818",
"260972069293896305361331050164952443697"
]
},
"source": "https://github.com/envoyproxy/envoy/commit/a79ca225f1ed924b855dff8a26bd7f7cdb84e694",
"target": {
"file": "source/common/tcp_proxy/tcp_proxy.h"
},
"deprecated": false,
"signature_type": "Line",
"signature_version": "v1"
},
{
"id": "CVE-2021-43824-d54b575d",
"digest": {
"threshold": 0.9,
"line_hashes": [
"146243477446113422387021212725253250778",
"48539946143607539866181123457421037495",
"283468910120726656487263215273247794220",
"32816829629574534818331468211218975208",
"167487698232686579647343259536732486616",
"18932793910309592312745692489877318569",
"190222441294940987692714025372522320194",
"233481120278761949454860284316900076892",
"33182693539138785849824461743826464632",
"238411867963402661331142337279192022640"
]
},
"source": "https://github.com/envoyproxy/envoy/commit/af50070ee60866874b0a9383daf9364e884ded22",
"target": {
"file": "source/common/tcp_proxy/tcp_proxy.cc"
},
"deprecated": false,
"signature_type": "Line",
"signature_version": "v1"
},
{
"id": "CVE-2021-43824-dc8d3820",
"digest": {
"length": 528,
"function_hash": "83990222759686494038875668905777786185"
},
"source": "https://github.com/envoyproxy/envoy/commit/4aaf9593152c6996b9da384c8918e9ad4f0abd4d",
"target": {
"file": "source/common/conn_pool/conn_pool_base.cc",
"function": "ConnPoolImplBase::closeIdleConnectionsForDrainingPool"
},
"deprecated": false,
"signature_type": "Function",
"signature_version": "v1"
},
{
"id": "CVE-2021-43824-efb2c5e4",
"digest": {
"length": 711,
"function_hash": "63191530169222520921233896458439701262"
},
"source": "https://github.com/envoyproxy/envoy/commit/af50070ee60866874b0a9383daf9364e884ded22",
"target": {
"file": "source/common/tcp_proxy/tcp_proxy.cc",
"function": "Filter::onUpstreamEvent"
},
"deprecated": false,
"signature_type": "Function",
"signature_version": "v1"
},
{
"id": "CVE-2021-43824-f0c98cd4",
"digest": {
"threshold": 0.9,
"line_hashes": [
"211063805449318930197667500157467379330",
"238149429280769817104751274898789662521",
"155508904057016497276277837828561242331",
"306263256694188145409853147140795887683",
"24621026682503930056724633583760538450",
"210759516705868193041331552012792706907",
"268100365964683135363265243678321089408",
"116993638250131326183953285211810091083",
"57246520075670457973995740670893215413",
"194433285147185661463287816608904302305",
"245699478661219870215728951569204544048",
"286440446911758131586479113237388457926",
"33382072507043576477734303938545662581",
"298229981597606534667320296045042459684",
"173090808602105440099610064642968627733",
"210942585548006467924962946211585504886",
"193341038770066763728097793037333651465",
"340006873902019806079016649741212930377",
"286206063645562425499514746822691310145",
"291017590637862723045538078816014658015"
]
},
"source": "https://github.com/envoyproxy/envoy/commit/4aaf9593152c6996b9da384c8918e9ad4f0abd4d",
"target": {
"file": "source/common/conn_pool/conn_pool_base.cc"
},
"deprecated": false,
"signature_type": "Line",
"signature_version": "v1"
},
{
"id": "CVE-2021-43824-f21ad525",
"digest": {
"threshold": 0.9,
"line_hashes": [
"13763891093658840408709216253600349407",
"199331892274894036869438950256051462149",
"29210709294056896109510237386162307151"
]
},
"source": "https://github.com/envoyproxy/envoy/commit/9371333230b1a6e1be2eccf4868771e11af6253a",
"target": {
"file": "test/extensions/filters/http/jwt_authn/filter_integration_test.cc"
},
"deprecated": false,
"signature_type": "Line",
"signature_version": "v1"
}
],
"vanir_signatures_modified": "2026-10-20T14:32:28Z"
}
}
],
"modified": "2026-10-20T14:32:28.111872150Z",
"provider": "osv",
"references": [
"https://github.com/envoyproxy/envoy/security/advisories/GHSA-vj5m-rch8-5r2p",
"https://github.com/envoyproxy/envoy/commit/9371333230b1a6e1be2eccf4868771e11af6253a"
],
"provider_metadata": {}
},
"related_cves": [
{
"value": "CVE-2021-43824",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 389707,
"published_at": "2022-02-22T23:15:10.813+00:00"
}