CVE-2023-4785 | Denial of Service in gRPC Core

Lack of error handling in the TCP server in Google's gRPC starting version 1.23 on posix-compatible platforms (ex. Linux) allows an attacker to cause a denial of service by initiating a significant number of connections with the server. Note that gRPC C++ Python, and Ruby are affected, but gRPC Java, and Go are NOT affected.

Published: 2023-09-13 Last update: 2026-01-12 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-4785 is rated Low Risk (34.5/100): CVSS High severity, with low exploitation likelihood (EPSS 0.04%). 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-2023-4785

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 2026-04-19 0.06% 0.04% -0.01%
2 2026-03-04 0.02% 0.06% +0.04%
3 2025-11-21 — 0.02% —

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-4785

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H 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:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H 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:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2023-4785

GitHub Security Advisory for CVE-2023-4785

GHSA-p25m-jpj4-qcrr · Severity: high · Ecosystem: rubygems — Denial of Service Vulnerability in gRPC TCP Server (Posix-compatible platforms)

OS Trackers for CVE-2023-4785

vendor priority summary link
alpine — CVE-2023-4785: 1 source package rows (grpc); 1 state rows across 1 repos (3.18-community); fixed 0, open 1. https://security.alpinelinux.org/vuln/CVE-2023-4785
debian not yet assigned CVE-2023-4785 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-2023-4785
redhat medium — https://access.redhat.com/security/cve/CVE-2023-4785
suse high CVE-2023-4785 severity important: SUSE including 39 source package names (grpc, grpc-devel, …), 207 product×package rows across 42 product lines (Image SLES15-SP4-BYOS-Azure, Image SLES15-SP4-HPC-BYOS-Azure, … (42 product lines)): Will Not Fix 139, Fixed 64, Known Not Affected 4. https://www.suse.com/security/cve/CVE-2023-4785/
ubuntu medium CVE-2023-4785 medium priority: Ubuntu including 1 source packages (grpc), 12 status rows across 12 suites (bionic, focal, jammy, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): needs-triage 7, ignored 5. https://ubuntu.com/security/CVE-2023-4785

Affected software / configurations for CVE-2023-4785

Vendor Product Version Raw CPE
grpc grpc >= 1.23.0, < 1.53.2 cpe:2.3:a:grpc:grpc:*:*:*:*:*:-:*:*
grpc grpc >= 1.54.0, < 1.54.3 cpe:2.3:a:grpc:grpc:*:*:*:*:*:-:*:*
grpc grpc >= 1.55.0, < 1.55.3 cpe:2.3:a:grpc:grpc:*:*:*:*:*:-:*:*
grpc grpc 1.56.0 cpe:2.3:a:grpc:grpc:1.56.0:*:*:*:*:-:*:*

References for CVE-2023-4785

cvelogic Threat Intelligence