# CVE-2023-4527: Glibc: stack read overflow in getaddrinfo in no-aaaa mode

> A stack read overflow in glibc's getaddrinfo allows attackers to disclose stack contents or cause crashes via large TCP DNS responses in no-aaaa mode.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/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:** 18 Sep 2023
- **Updated:** 14 Oct 2026
- **Also known as:** AZL-34732, BELL-CVE-2023-4527, DEBIAN-CVE-2023-4527, GHSA-hmf7-f8gf-8f4p

## What is CVE-2023-4527?

CVE-2023-4527 is a medium-severity vulnerability in Fedoraproject Fedora, published on 18 Sep 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A flaw was found in glibc. When the getaddrinfo function is called with the AF_UNSPEC address family and the system is configured with no-aaaa mode via /etc/resolv.conf, a DNS response via TCP larger than 2048 bytes can potentially disclose stack contents through the function returned address data, and may cause a crash.

Weakness: CWE-125 (Out-of-bounds Read), CWE-121 (Stack-based Buffer Overflow)

## Which versions are affected by CVE-2023-4527?

It affects 27 products.


Products: Fedoraproject Fedora, Gnu Glibc, Netapp H300s Firmware, Netapp H410c Firmware, Netapp H410s Firmware, Netapp H500s Firmware, Netapp H700s Firmware, Redhat Codeready Linux Builder Eus, Redhat Codeready Linux Builder Eus for Power Little Endian, Redhat Codeready Linux Builder Eus for Power Little Endian Eus, Redhat Codeready Linux Builder for Arm64, Redhat Codeready Linux Builder for Arm64 Eus, Redhat Codeready Linux Builder for Ibm Z Systems, Redhat Codeready Linux Builder for Ibm Z Systems Eus, Redhat Enterprise Linux, Redhat Enterprise Linux Eus, Redhat Enterprise Linux for Arm 64, Redhat Enterprise Linux for Arm 64 Eus, Redhat Enterprise Linux for Ibm Z Systems, Redhat Enterprise Linux for Ibm Z Systems Eus and 7 more.

## How do I fix CVE-2023-4527?

Apply the vendor's patch.

## Is CVE-2023-4527 being exploited?

There is no known exploitation of CVE-2023-4527 in the wild and no public exploit code.

## Other vulnerabilities in Fedoraproject Fedora

- [CVE-2024-4577](https://insights.sbomify.com/CVE-2024-4577/): PHP-CGI OS Command Injection (critical 9.8, exploited in the wild)
- [CVE-2021-39226](https://insights.sbomify.com/CVE-2021-39226/): Grafana Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2019-5544](https://insights.sbomify.com/CVE-2019-5544/): VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2024-4947](https://insights.sbomify.com/CVE-2024-4947/): Google Chromium V8 Type Confusion (critical 9.6, exploited in the wild)
- [CVE-2024-4671](https://insights.sbomify.com/CVE-2024-4671/): Google Chromium Visuals Use-After-Free (critical 9.6, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-4527 and fix it if it is affected.

What it is: CVE-2023-4527 is a medium-severity vulnerability in Fedoraproject Fedora, published on 18 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-2023-4527 in the wild and no public exploit code.

Affected product: Fedoraproject Fedora. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2023-4527/ (Markdown: https://insights.sbomify.com/CVE-2023-4527/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-4527
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-4527
- OSV: https://osv.dev/vulnerability/CVE-2023-4527

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-4527/
Summaries are generated and may contain mistakes; the official description above is the record.