Multiple vulnerabilities in Envoy



Risk High
Patch available YES
Number of vulnerabilities 5
CVE-ID CVE-2021-32778
CVE-2021-32780
CVE-2021-32781
CVE-2021-32777
CVE-2021-32779
CWE-ID CWE-834
CWE-754
CWE-416
CWE-285
CWE-200
Exploitation vector Network
Public exploit N/A
Vulnerable software
 envoy
Server applications / IDS/IPS systems, Firewalls and proxy servers

Vendor Cloud Native Computing Foundation

Security Bulletin

This security bulletin contains information about 5 vulnerabilities.

1) Excessive Iteration

EUVDB-ID: #VU56147

Risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-32778

CWE-ID: CWE-834 - Excessive Iteration

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to the Envoy is configured with high limit on H/2 concurrent streams. A remote attacker can cause a denial of service condition on the target system. 

Mitigation

Install updates from vendor's website.

Vulnerable software versions

envoy: 1.16.0 - 1.19.0

CPE2.3 External links

https://www.envoyproxy.io/docs/envoy/v1.19.0/version_history/version_history
https://github.com/envoyproxy/envoy/security/advisories/GHSA-3xh3-33v5-chcc


Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) Improper Check for Unusual or Exceptional Conditions

EUVDB-ID: #VU56148

Risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-32780

CWE-ID: CWE-754 - Improper Check for Unusual or Exceptional Conditions

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to incorrect handling of H/2 GOAWAY followed by SETTINGS frames. A remote attacker can cause a denial of service condition on the target system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

envoy: 1.18.0 - 1.19.0

CPE2.3
External links

https://github.com/envoyproxy/envoy/security/advisories/GHSA-j374-mjrw-vvp8
https://www.envoyproxy.io/docs/envoy/v1.19.0/version_history/version_history


Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

3) Use-after-free

EUVDB-ID: #VU56107

Risk: Medium

CVSSv4.0: 4.6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-32781

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a use-after-free error when processing HTTP requests and responses in Envoy. A remote attacker can send a specially crafted HTTP request or response to the application, trigger a use-after-free error and perform a denial of service attack.

Successful exploitation of the vulnerability requires presence of extension that can modify and increase the size of request or response bodies.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

envoy: 1.16.0 - 1.19.0

CPE2.3
External links

https://www.envoyproxy.io/docs/envoy/v1.19.0/version_history/version_history
https://github.com/envoyproxy/envoy/security/advisories/GHSA-5vhv-gp9v-42qv


Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

4) Improper Authorization

EUVDB-ID: #VU56106

Risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-32777

CWE-ID: CWE-285 - Improper Authorization

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass authorization process.

The vulnerability exists due to an error in ext-authz extension when sending request headers to the external authorization service in Envoy. The application sends only the last header instead of merging multiple value headers according to the HTTP specification. A remote attacker can bypass authorization process and gain unauthorized access to the application, if ext-authz extension is used.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

envoy: 1.16.0 - 1.19.0

CPE2.3
External links

https://github.com/envoyproxy/envoy/security/advisories/GHSA-6g4j-5vrw-2m8h
https://www.envoyproxy.io/docs/envoy/v1.19.0/version_history/version_history


Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

5) Information disclosure

EUVDB-ID: #VU56149

Risk: High

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2021-32779

CWE-ID: CWE-200 - Information exposure

Exploit availability: No

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to incorrectly handling of URI "#fragment" element as part of the path element. A remote attacker can send a specially crafted request and gain unauthorized access to sensitive information on the system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

envoy: 1.16.0 - 1.19.0

CPE2.3
External links

https://www.envoyproxy.io/docs/envoy/v1.19.0/version_history/version_history
https://github.com/envoyproxy/envoy/security/advisories/GHSA-r222-74fw-jqr9


Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.



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