// For flags

CVE-2023-32731

Information leak in gRPC

Severity Score

7.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

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. If leveraged, say, between a proxy and a backend, 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. We recommend upgrading beyond the commit contained in https://github.com/grpc/grpc/pull/33005 https://github.com/grpc/grpc/pull/33005

A flaw was found in gRPC. This flaw allows a remote attacker to obtain sensitive information, caused by a flaw when the gRPC HTTP2 stack raised a header size exceeded error. By sending a specially crafted request, an attacker can obtain sensitive information, and use this information to launch further attacks against the affected system.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
High
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
Complete
Integrity
None
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2023-05-12 CVE Reserved
  • 2023-06-09 CVE Published
  • 2024-09-26 CVE Updated
  • 2025-03-30 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-440: Expected Behavior Violation
CAPEC
  • CAPEC-220: Client-Server Protocol Manipulation
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Grpc
Search vendor "Grpc"
 Grpc
Search vendor "Grpc" for product "Grpc"
 >= 1.53.0 < 1.55.0
Search vendor "Grpc" for product "Grpc" and version " >= 1.53.0 < 1.55.0"
-
Affected