Skip to content
Fencer Vulns
high 7.4

CVE-2023-32731 json

Information leak in gRPC

published 2023-06-09 3 y ago modified 2026-09-10 1 mo ago also GHSA-cfgp-2977-2fmm , PYSEC-2026-1427 , EUVD-2023-2030

cvss
7.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 42%
public exploits
0
none known

Summary

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

Patch / fix

  • maven io.grpc:grpc-protobuf 1.53.1, 1.54.2
  • pypi grpcio 1.53.1, 1.54.2
  • rubygems grpc 1.53.1, 1.54.2
  • grpc grpc 1.55.0
  • rhc-worker-playbook RHEL 9 0.1.10-1.el9_5

red hat advisories RHSA-2024:10761

  • re2 SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Module for Public Cloud 15 SP5 +5 more 20240201-150400.9.3.1
  • grpc SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Module for Public Cloud 15 SP5 +6 more 1.60.0-150400.8.3.2
  • protobuf SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Module for Python 3 15 SP5 +16 more 25.1-150400.9.3.1
  • abseil-cpp SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Workstation Extension 15 SP5 +13 more 20230802.1-150400.10.4.1
  • python-abseil SLE Module for Python 3 15 SP5, openSUSE Leap 15.5 1.4.0-150400.9.3.1
  • python-grpcio SLE Module for Python 3 15 SP5, openSUSE Leap 15.5 1.60.0-150400.9.3.2
  • opencensus-proto openSUSE Leap 15.5 0.3.0+git.20200721-150400.9.3.1

suse advisories SUSE-SU-2024:0573-1

  • python-grpcio openSUSE Tumbleweed 1.84.0-1.1

opensuse advisories openSUSE-SU-2026:11926-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-32731 updated cvss 7.4

gRPC: sensitive information disclosure

  • Red Hat OpenShift Container Platform 4 grpc, grpc-cli, grpc-plugins, python3-grpcio
    affected: no fix available
  • Red Hat Enterprise Linux AppStream (v. 9) rhc-worker-playbook 0.1.10-1.el9_5
    fixed: vendor fix RHSA-2024:10761
  • Red Hat Enterprise Linux 8 rhc-worker-playbook
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.50% chance of exploitation in the next 30 days, higher than 42% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
OSV 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H
GitHub 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H

Affected packages

ecosystem package affected fixed in
maven io.grpc:grpc-protobuf
>=1.53.0, <1.53.1
>=1.54.0, <1.54.2
1.53.1
1.54.2
pypi grpcio
>=1.53.0, <1.53.1
>=1.54.0, <1.54.2
1.53.1
1.54.2
rubygems grpc
>=1.53.0, <1.53.1
>=1.54.0, <1.54.2
1.53.1
1.54.2

Affected products

  • Google gRPC
  • grpc grpc

Classification

Weakness
  • CWE-440 Expected Behavior Violation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.