CVE-2021-43826— Crash when tunneling TCP over HTTP in Envoy
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I. Basic Information for CVE-2021-43826
Vulnerability Information
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Vulnerability Title
Crash when tunneling TCP over HTTP in Envoy
Source: NVD (National Vulnerability Database)
Vulnerability Description
Envoy is an open source edge and service proxy, designed for cloud-native applications. In affected versions of Envoy a crash occurs when configured for :ref:`upstream tunneling <envoy_v3_api_field_extensions.filters.network.tcp_proxy.v3.TcpProxy.tunneling_config>` and the downstream connection disconnects while the the upstream connection or http/2 stream is still being established. There are no workarounds for this issue. Users are advised to upgrade.
Source: NVD (National Vulnerability Database)
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source: NVD (National Vulnerability Database)
Vulnerability Type
释放后使用
Source: NVD (National Vulnerability Database)
Vulnerability Title
Envoy 资源管理错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Envoy是一款开源的分布式代理服务器。 Envoy 存在资源管理错误漏洞，该漏洞源于当为上游隧道配置envoy_v3_api_field_extensions.filters.network.tcp_proxy.v3.TcpProxy.tunneling_config时发生崩溃，并且下游连接断开，而上游连接或 http/2 流仍然存在。 没有解决此问题的方法。 建议用户升级。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
| Vendor | Product | Affected Versions | CPE | Subscribe |
|---|---|---|---|---|
| envoyproxy | envoy | < 1.18.6 | - |
II. Public POCs for CVE-2021-43826
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|---|
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- https://github.com/envoyproxy/envoy/security/advisories/GHSA-cmx3-fvgf-83mfx_refsource_CONFIRM
- https://nvd.nist.gov/vuln/detail/CVE-2021-43826
Same Patch Batch · envoyproxy · 2022-02-22 · 8 CVEs total
| CVE-2022-21655 | 7.5 HIGH | Incorrect handling of internal redirects results in crash in Envoy |
| CVE-2021-43824 | 7.5 HIGH | Null pointer dereference in envoy |
| CVE-2022-21654 | 7.4 HIGH | Incorrect configuration handling allows TLS session re-use without re-validation in Envoy |
| CVE-2022-21656 | 7.4 HIGH | X.509 subjectAltName matching bypass in Envoy |
| CVE-2022-21657 | 6.8 MEDIUM | X.509 Extended Key Usage and Trust Purposes bypass in Envoy |
| CVE-2021-43825 | 6.1 MEDIUM | Use-after-free in Envoy |
| CVE-2022-23606 | 4.4 MEDIUM | Crash when a cluster is deleted in Envoy |
IV. Related Vulnerabilities
Same product: envoy
- CVE-2026-6994
Envoy Query Parameter header_mutation.cc params.add injectio - CVE-2026-26330
Envoy global rate limit may crash when the response phase li - CVE-2026-26311
Envoy HTTP: filter chain execution on reset streams causing - CVE-2026-26310
Crash for scoped ip address in Envoy during DNS - CVE-2026-26309
Envoy has an off-by-one write in JsonEscaper::escapeString()
Same vendor: envoyproxy
- CVE-2026-26330
Envoy global rate limit may crash when the response phase li - CVE-2026-26311
Envoy HTTP: filter chain execution on reset streams causing - CVE-2026-26310
Crash for scoped ip address in Envoy during DNS - CVE-2026-26309
Envoy has an off-by-one write in JsonEscaper::escapeString() - CVE-2026-26308
Envoy has an RBAC Header Validation Bypass via Multi-Value H
V. Comments for CVE-2021-43826
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