Multiple vulnerabilities in gRPC

Published: 2023-08-21

Risk	Medium
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2023-32731 CVE-2023-32732
CWE-ID	CWE-20
Exploitation vector	Network
Public exploit	N/A
Vulnerable software	gRPC Server applications / Frameworks for developing and running applications
Vendor	grpc

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Input validation error

EUVDB-ID: #VU79797

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-2023-32731

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

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

The vulnerability exists due to insufficient validation of user-supplied input when parsing HTTP2 requests. When gRPC HTTP2 stack raised a header size exceeded error, it skipped parsing the rest of the HPACK frame. This caused any HPACK table mutations to also be skipped, resulting in a desynchronization of HPACK tables between sender and receiver. This could lead to requests from the proxy being interpreted as containing headers from different proxy clients, leading to an information leak that can be used for privilege escalation or data exfiltration.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

gRPC: before 1.53.0

CPE2.3

cpe:2.3:a:grpc:grpc:*:*:*:*:*:*:*:*

External links

https://github.com/grpc/grpc/pull/32309
https://github.com/grpc/grpc/pull/33005

Q & A

Can this vulnerability be exploited remotely?

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

Is there known malware, which exploits this vulnerability?

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

2) Input validation error

EUVDB-ID: #VU79796