CVE-2023-33953
gRPC HPACK Parser Unbounded CPU Consumption and Memory Buffering Vulnerability
Description
gRPC contains a vulnerability that allows hpack table accounting errors could lead to unwanted disconnects between clients and servers in exceptional cases/ Three vectors were found that allow the following DOS attacks: - Unbounded memory buffering in the HPACK parser - Unbounded CPU consumption in the HPACK parser The unbounded CPU consumption is down to a copy that occurred per-input-block in the parser, and because that could be unbounded due to the memory copy bug we end up with an O(n^2) parsing loop, with n selected by the client. The unbounded memory buffering bugs: - The header size limit check was behind the string reading code, so we needed to first buffer up to a 4 gigabyte string before rejecting it as longer than 8 or 16kb. - HPACK varints have an encoding quirk whereby an infinite number of 0’s can be added at the start of an integer. gRPC’s hpack parser needed to read all of them before concluding a parse. - gRPC’s metadata overflow check was performed per frame, so that the following sequence of frames could cause infinite buffering: HEADERS: containing a: 1 CONTINUATION: containing a: 2 CONTINUATION: containing a: 3 etc…
INFO
Published Date :
Aug. 9, 2023, 1:15 p.m.
Last Modified :
Aug. 17, 2023, 2:15 p.m.
Source :
[email protected]
Remotely Exploitable :
Yes !
Impact Score :
3.6
Exploitability Score :
3.9
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2023-33953.
| URL | Resource |
|---|---|
| https://cloud.google.com/support/bulletins#gcp-2023-022 | Vendor Advisory |
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2023-33953 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2023-33953 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
Initial Analysis by [email protected]
Aug. 17, 2023
Action Type Old Value New Value Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Changed Reference Type https://cloud.google.com/support/bulletins#gcp-2023-022 No Types Assigned https://cloud.google.com/support/bulletins#gcp-2023-022 Vendor Advisory Added CWE NIST CWE-770 Added CWE NIST CWE-834 Added CPE Configuration OR *cpe:2.3:a:grpc:grpc:*:*:*:*:*:-:*:* versions up to (excluding) 1.53.2 *cpe:2.3:a:grpc:grpc:*:*:*:*:*:-:*:* versions from (including) 1.54.0 up to (excluding) 1.54.3 *cpe:2.3:a:grpc:grpc:*:*:*:*:*:-:*:* versions from (including) 1.55.0 up to (excluding) 1.55.2 *cpe:2.3:a:grpc:grpc:*:*:*:*:*:-:*:* versions from (including) 1.56.0 up to (excluding) 1.56.2
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2023-33953 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2023-33953
weaknesses.
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
0.08 }} 0.02%
score
0.32899
percentile