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

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

Published: 2023-06-09 Last update: 2025-02-13 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-32732 is rated Low Risk (22.8/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-32732

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-11-21 0.15% 0.02% -0.13%
2 2025-11-18 0.02% 0.15% +0.13%
3 2025-04-15 — 0.02% —

Full EPSS history (12 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-32732

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 1.4 [email protected]
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 1.4 [email protected]

Weakness enumeration for CVE-2023-32732

GitHub Security Advisory for CVE-2023-32732

GHSA-9hxf-ppjv-w6rq · Severity: medium · Ecosystem: maven — gRPC connection termination issue

OS Trackers for CVE-2023-32732

vendor priority summary link
debian not yet assigned CVE-2023-32732 not yet assigned priority: Debian including 1 source packages (grpc), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 5. https://security-tracker.debian.org/tracker/CVE-2023-32732
redhat medium — https://access.redhat.com/security/cve/CVE-2023-32732
suse medium CVE-2023-32732 severity moderate: SUSE including 37 source package names (grpc, grpc-devel, …), 116 product×package rows across 38 product lines (Image SLES15-SP4-BYOS-Azure, Image SLES15-SP4-HPC-BYOS-Azure, … (38 product lines)): Fixed 64, Will Not Fix 48, Known Not Affected 4. https://www.suse.com/security/cve/CVE-2023-32732/
ubuntu medium CVE-2023-32732 medium priority: Ubuntu including 1 source packages (grpc), 13 status rows across 13 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 6, needs-triage 6, released 1. https://ubuntu.com/security/CVE-2023-32732

Affected software / configurations for CVE-2023-32732

Vendor Product Version Raw CPE
grpc grpc < 1.53.0 cpe:2.3:a:grpc:grpc:*:*:*:*:*:*:*:*
fedoraproject fedora 37 cpe:2.3:o:fedoraproject:fedora:37:*:*:*:*:*:*:*
fedoraproject fedora 38 cpe:2.3:o:fedoraproject:fedora:38:*:*:*:*:*:*:*

References for CVE-2023-32732

cvelogic Threat Intelligence