# CVE-2023-4785: Denial of Service in gRPC Core > An attacker can cause a denial of service in gRPC Core on POSIX platforms by initiating numerous connections due to lack of error handling. - **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 13 Sep 2023 - **Updated:** 12 Jan 2026 - **Also known as:** AZL-34772, BELL-CVE-2023-4785, DEBIAN-CVE-2023-4785, ECHO-050a-2d98-bb04, GHSA-p25m-jpj4-qcrr, OESA-2023-1682, OESA-2023-1726, PYSEC-2026-1428, UBUNTU-CVE-2023-4785 ## What is CVE-2023-4785? CVE-2023-4785 is a high-severity denial of service vulnerability in Google gRPC, published on 13 Sep 2023. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description 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. Weakness: CWE-248 (Uncaught Exception) ## Which versions are affected by CVE-2023-4785? 15 open source packages ship an affected version, including grpc and grpcio. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `grpc` | RubyGems | From 1.53.0 | 1.53.2 | | `grpc` | RubyGems | From 1.53.0 | 1.53.2 | | `grpc` | RubyGems | From 1.54.0 | 1.54.3 | | `grpc` | RubyGems | From 1.54.0 | 1.54.3 | | `grpc` | RubyGems | From 1.55.0 | 1.55.3 | | `grpc` | RubyGems | From 1.55.0 | 1.55.3 | | `grpc` | RubyGems | From 1.56.0 | 1.56.2 | | `grpc` | RubyGems | From 1.56.0 | 1.56.2 | | `grpcio` | PyPI | From 1.53.0 | 1.53.2 | | `grpcio` | PyPI | From 1.53.0 | 1.53.2 | | `grpcio` | PyPI | From 1.54.0 | 1.54.3 | | `grpcio` | PyPI | From 1.54.0 | 1.54.3 | | `grpcio` | PyPI | From 1.55.0 | 1.55.3, 1.54.3, 1.53.2 | | `grpcio` | PyPI | From 1.55.0 | 1.55.3 | | `grpcio` | PyPI | From 1.55.0 | 1.55.3 | Products: Grpc Grpc. ## How do I fix CVE-2023-4785? Upgrade grpc to a fixed version for your release line: 1.53.2, 1.54.3, 1.55.3 or 1.56.2. ## Is CVE-2023-4785 being exploited? There is no known exploitation of CVE-2023-4785 in the wild and no public exploit code. ## Other vulnerabilities in Google gRPC - [CVE-2017-9431](https://insights.sbomify.com/CVE-2017-9431/): Memory corruption in n/a (critical 9.8) - [CVE-2017-8359](https://insights.sbomify.com/CVE-2017-8359/): Use after free in n/a (critical 9.8) - [CVE-2017-7860](https://insights.sbomify.com/CVE-2017-7860/): Memory corruption in n/a (critical 9.8) - [CVE-2017-7861](https://insights.sbomify.com/CVE-2017-7861/): Memory corruption in n/a (critical 9.8) - [CVE-2026-33186](https://insights.sbomify.com/CVE-2026-33186/): gRPC-Go has an authorization bypass via missing leading slash in :path (critical 9.1) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2023-4785 and fix it if it is affected. What it is: CVE-2023-4785 is a high-severity denial of service vulnerability in Google gRPC, published on 13 Sep 2023. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2023-4785 in the wild and no public exploit code. Affected packages and fixed versions: - grpc (RubyGems): affected from 1.53.0; fixed in 1.53.2 - grpc (RubyGems): affected from 1.53.0; fixed in 1.53.2 - grpc (RubyGems): affected from 1.54.0; fixed in 1.54.3 - grpc (RubyGems): affected from 1.54.0; fixed in 1.54.3 - grpc (RubyGems): affected from 1.55.0; fixed in 1.55.3 - grpc (RubyGems): affected from 1.55.0; fixed in 1.55.3 - grpc (RubyGems): affected from 1.56.0; fixed in 1.56.2 - grpc (RubyGems): affected from 1.56.0; fixed in 1.56.2 - grpcio (PyPI): affected from 1.53.0; fixed in 1.53.2 - grpcio (PyPI): affected from 1.53.0; fixed in 1.53.2 - grpcio (PyPI): affected from 1.54.0; fixed in 1.54.3 - grpcio (PyPI): affected from 1.54.0; fixed in 1.54.3 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2023-4785/ (Markdown: https://insights.sbomify.com/CVE-2023-4785/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2023-4785 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-4785 - OSV: https://osv.dev/vulnerability/CVE-2023-4785 --- From sbomify Insights: https://insights.sbomify.com/CVE-2023-4785/ Summaries are generated and may contain mistakes; the official description above is the record.