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NVD / CVE Program· CNA Google

CVE-2023-32732: Denial-of-Service in gRPC

Noroxi assessment

Priority: Monitor (action score 21/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.52% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: io.grpc:grpc-protobuf (Maven) 1.53.1, 1.54.2; grpc (openSUSE:Leap 15.5) 1.60.0-150400.8.3.2; opencensus-proto (openSUSE:Leap 15.5) 0.3.0+git.20200721-150400.9.3.1.

Low priority for now. Upgrade to io.grpc:grpc-protobuf (Maven) 1.53.1, 1.54.2; grpc (openSUSE:Leap 15.5) 1.60.0-150400.8.3.2; opencensus-proto (openSUSE:Leap 15.5) 0.3.0+git.20200721-150400.9.3.1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

gRPC contains a vulnerability whereby a client can cause a termination of connection between a HTTP2 proxy and a gRPC server: a base64 encoding error for `-bin` suffixed headers will result in a disconnection by the gRPC server, but is typically allowed by HTTP2 proxies. We recommend upgrading beyond the commit in  https://github.com/grpc/grpc/pull/32309 https://www.google.com/url

MediumCVSS 5.3 · v3.1—No exploit Fix available
Published
Jun 9, 2023
Updated
Jun 17, 2026
EPSS
0.5% · 44th percentile

Report tools

JSON

Action score

21

Monitor

Low priority for now.

CVSS
21 / 40 · 5.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
5.3
CNA · Google
5.3
agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2023-32732

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
grpcgrpc
fedoraprojectfedora

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • fedoraproject fedora37
  • fedoraproject fedora38
  • grpc grpcbefore 1.53.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Google). Independent of NVD's CPE analysis and usually ahead of it.

  • Google gRPC

    • 1.53 and later · before 1.54affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12grpcfrom 0—
Mavenio.grpc:grpc-protobuffrom 1.53.0 · before 1.53.11.53.1
Mavenio.grpc:grpc-protobuffrom 1.54.0 · before 1.54.21.54.2
openSUSE:Leap 15.5grpcbefore 1.60.0-150400.8.3.21.60.0-150400.8.3.2
openSUSE:Leap 15.5opencensus-protobefore 0.3.0+git.20200721-150400.9.3.10.3.0+git.20200721-150400.9.3.1
openSUSE:Leap 15.5python-abseilbefore 1.4.0-150400.9.3.11.4.0-150400.9.3.1
openSUSE:Leap 15.5python-grpciobefore 1.60.0-150400.9.3.21.60.0-150400.9.3.2
openSUSE:Leap 15.5re2before 20240201-150400.9.3.120240201-150400.9.3.1
openSUSE:Leap Micro 5.3abseil-cppbefore 20230802.1-150400.10.4.120230802.1-150400.10.4.1
openSUSE:Leap Micro 5.3protobufbefore 25.1-150400.9.3.125.1-150400.9.3.1
openSUSE:Tumbleweedpython-grpciobefore 1.84.0-1.11.84.0-1.1
PyPIgrpciofrom 1.53.0 · before 1.53.11.53.1
PyPIgrpciofrom 1.54.0 · before 1.54.21.54.2
RubyGemsgrpcfrom 1.53.0 · before 1.53.11.53.1
RubyGemsgrpcfrom 1.54.0 · before 1.54.21.54.2
SUSE:Linux Enterprise Installer Updates 15 SP4abseil-cppbefore 20230802.1-150400.10.4.120230802.1-150400.10.4.1
SUSE:Linux Enterprise Installer Updates 15 SP4protobufbefore 25.1-150400.9.3.125.1-150400.9.3.1
SUSE:Linux Enterprise Module for Basesystem 15 SP5grpcbefore 1.60.0-150400.8.3.21.60.0-150400.8.3.2
SUSE:Linux Enterprise Module for Basesystem 15 SP5re2before 20240201-150400.9.3.120240201-150400.9.3.1
SUSE:Linux Enterprise Module for Python 3 15 SP5python-abseilbefore 1.4.0-150400.9.3.11.4.0-150400.9.3.1
SUSE:Linux Enterprise Module for Python 3 15 SP5python-grpciobefore 1.60.0-150400.9.3.21.60.0-150400.9.3.2

Same product

grpc: all records

Other highest-scoring records for the same primary product.

  • CVE-2020-7768The package grpc before 1.24.4; the package @grpc/grpc-js before 1.1.8 are vulnerable to Prototype Pollution via loadPackageDefinition.
    40Plan
  • CVE-2017-9431Google gRPC before 2017-04-05 has an out-of-bounds write caused by a heap-based buffer overflow related to core/lib/iomgr/error.c.
    40Plan
  • CVE-2017-8359Google gRPC before 2017-03-29 has an out-of-bounds write caused by a heap-based use-after-free related to the grpc_call_destroy function in
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2023-1428Jun 9, 2023 · Denial-of-Service in gRPC
    30Monitor
  • ← EarlierCVE-2023-32731Jun 9, 2023 · Information leak in gRPC
    30Monitor
  • Later →CVE-2023-33953Aug 9, 2023 · Denial-of-Service in gRPC
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Maven:io.grpc:grpc-protobuf1.53.1Package registry (OSV)
Maven:io.grpc:grpc-protobuf1.54.2Package registry (OSV)
opensuse:abseil-cpp20230802.1-150400.10.4.1 · openSUSE:Leap Micro 5.3Package registry (OSV)
opensuse:grpc1.60.0-150400.8.3.2 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:opencensus-proto0.3.0+git.20200721-150400.9.3.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:protobuf25.1-150400.9.3.1 · openSUSE:Leap Micro 5.3Package registry (OSV)
opensuse:python-abseil1.4.0-150400.9.3.1 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:python-grpcio1.60.0-150400.9.3.2 · openSUSE:Leap 15.5Package registry (OSV)
opensuse:re220240201-150400.9.3.1 · openSUSE:Leap 15.5Package registry (OSV)
PyPI:grpcio1.53.1Package registry (OSV)
PyPI:grpcio1.54.2Package registry (OSV)
RubyGems:grpc1.53.1Package registry (OSV)
RubyGems:grpc1.54.2Package registry (OSV)
suse:abseil-cpp20230802.1-150400.10.4.1 · SUSE:Linux Enterprise Installer Updates 15 SP4Package registry (OSV)
suse:grpc1.60.0-150400.8.3.2 · SUSE:Linux Enterprise Module for Basesystem 15 SP5Package registry (OSV)
suse:protobuf25.1-150400.9.3.1 · SUSE:Linux Enterprise Installer Updates 15 SP4Package registry (OSV)
suse:python-abseil1.4.0-150400.9.3.1 · SUSE:Linux Enterprise Module for Python 3 15 SP5Package registry (OSV)
suse:python-grpcio1.60.0-150400.9.3.2 · SUSE:Linux Enterprise Module for Python 3 15 SP5Package registry (OSV)
suse:re220240201-150400.9.3.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP5Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
low · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
Low

Weakness class (CWE)

CWE-440 · Expected Behavior Violation

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records