Vulnerability in Google Grpc

CVE-2023-32731

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

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H.

EPSS exploit prediction

EPSS: 0.005 (41.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 41.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2023-32731: held from 0.005 to 0.005.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: -0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2023-32731?
CVE-2023-32731 is a high-severity vulnerability in Google Grpc, classified under Expected Behavior Violation. CVSS score: 7.4/10. Published 2023-06-09.
How severe is CVE-2023-32731?
High severity. CVSS v3 base score is 7.4 out of 10.
Is CVE-2023-32731 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.