CVE-2023-33953

描述

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…

如何修補 CVE-2023-33953

要修補 CVE-2023-33953,請將受影響套件升級到下列已修補版本。

• —升級至 1.53.2 或更新版本

CVE-2023-33953 正在被利用嗎?

低 — EPSS 為 0.4%,目前沒有觀察到大規模利用活動。

受影響套件(1)

• from 0, < 1.53.2

CVSS 分數

參考連結(5)

• ADVISORYgithub.com/advisories/GHSA-496j-2rq6-j6cc
• ADVISORYnvd.nist.gov/vuln/detail/CVE-2023-33953
• WEBcloud.google.com/support/bulletins#gcp-2023-022
• WEBgithub.com/rubysec/ruby-advisory-db/blob/master/gems/grpc/CVE-2023-33953.yml