# CVE-2023-2828: named's configured cache size limit can be significantly exceeded

> Attackers can exceed the configured cache size limit in BIND 9 recursive resolvers by manipulating query order, potentially causing resource exhaustion and denial of service.

- **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:** 21 Jun 2023
- **Updated:** 13 Feb 2025
- **Also known as:** ALSA-2023:4099, ALSA-2023:4100, ALSA-2023:4102, AZL-27203, AZL-27238, CLSA-2023-1688677755, CLSA-2023-1689008238, CLSA-2023-1689008612, CLSA-2023-1691576076, CLSA-2024-1735311722, DEBIAN-CVE-2023-2828, DLA-3498-1, GHSA-v668-ccv8-m5gx, OESA-2023-1384, OESA-2023-1505, RHSA-2023:4005, RHSA-2023:4037, RHSA-2023:4099, RHSA-2023:4100, RHSA-2023:4101, RHSA-2023:4102, RHSA-2023:4152, RHSA-2023:4153, RHSA-2023:4154, RHSA-2023:4332, RLSA-2023:4099, RLSA-2023:4100, RLSA-2023:4102, SUSE-SU-2023:2789-1, SUSE-SU-2023:2793-1, SUSE-SU-2023:2794-1, SUSE-SU-2023:2954-1, UBUNTU-CVE-2023-2828, USN-6183-2

## What is CVE-2023-2828?

CVE-2023-2828 is a high-severity denial of service vulnerability in Debian Debian Linux, published on 21 Jun 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Every `named` instance configured to run as a recursive resolver maintains a cache database holding the responses to the queries it has recently sent to authoritative servers. The size limit for that cache database can be configured using the `max-cache-size` statement in the configuration file; it defaults to 90% of the total amount of memory available on the host. When the size of the cache reaches 7/8 of the configured limit, a cache-cleaning algorithm starts to remove expired and/or least-recently used RRsets from the cache, to keep memory use below the configured limit.

It has been discovered that the effectiveness of the cache-cleaning algorithm used in `named` can be severely diminished by querying the resolver for specific RRsets in a certain order, effectively allowing the configured `max-cache-size` limit to be significantly exceeded.
This issue affects BIND 9 versions 9.11.0 through 9.16.41, 9.18.0 through 9.18.15, 9.19.0 through 9.19.13, 9.11.3-S1 through 9.16.41-S1, and 9.18.11-S1 through 9.18.15-S1.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2023-2828?

It affects 9 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `bind` | AlmaLinux:8 | All versions | 32:9.11.36-8.el8_8.1 |
| `bind-chroot` | AlmaLinux:8 | All versions | 32:9.11.36-8.el8_8.1 |
| `bind-devel` | AlmaLinux:8 | All versions | 32:9.11.36-8.el8_8.1 |
| `bind-export-devel` | AlmaLinux:8 | All versions | 32:9.11.36-8.el8_8.1 |
| `bind-export-libs` | AlmaLinux:8 | All versions | 32:9.11.36-8.el8_8.1 |
| `bind-libs` | AlmaLinux:8 | All versions | 32:9.11.36-8.el8_8.1 |
| `bind-libs-lite` | AlmaLinux:8 | All versions | 32:9.11.36-8.el8_8.1 |
| `bind-license` | AlmaLinux:8 | All versions | 32:9.11.36-8.el8_8.1 |
| `bind-lite-devel` | AlmaLinux:8 | All versions | 32:9.11.36-8.el8_8.1 |
| `bind-pkcs11` | AlmaLinux:8 | All versions | 32:9.11.36-8.el8_8.1 |
| `bind-pkcs11-devel` | AlmaLinux:8 | All versions | 32:9.11.36-8.el8_8.1 |
| `bind-pkcs11-libs` | AlmaLinux:8 | All versions | 32:9.11.36-8.el8_8.1 |
| `bind-pkcs11-utils` | AlmaLinux:8 | All versions | 32:9.11.36-8.el8_8.1 |
| `bind-sdb` | AlmaLinux:8 | All versions | 32:9.11.36-8.el8_8.1 |
| `bind-sdb-chroot` | AlmaLinux:8 | All versions | 32:9.11.36-8.el8_8.1 |
| `bind-utils` | AlmaLinux:8 | All versions | 32:9.11.36-8.el8_8.1 |
| `bind9.16` | AlmaLinux:8 | All versions | 32:9.16.23-0.14.el8_8.1.alma |
| `bind9.16-chroot` | AlmaLinux:8 | All versions | 32:9.16.23-0.14.el8_8.1.alma |
| `bind9.16-devel` | AlmaLinux:8 | All versions | 32:9.16.23-0.14.el8_8.1.alma |
| `bind9.16-dnssec-utils` | AlmaLinux:8 | All versions | 32:9.16.23-0.14.el8_8.1.alma |
| `bind9.16-doc` | AlmaLinux:8 | All versions | 32:9.16.23-0.14.el8_8.1.alma |
| `bind9.16-libs` | AlmaLinux:8 | All versions | 32:9.16.23-0.14.el8_8.1.alma |
| `bind9.16-license` | AlmaLinux:8 | All versions | 32:9.16.23-0.14.el8_8.1.alma |
| `bind9.16-utils` | AlmaLinux:8 | All versions | 32:9.16.23-0.14.el8_8.1.alma |
| `python3-bind` | AlmaLinux:8 | All versions | 32:9.11.36-8.el8_8.1 |
| `python3-bind9.16` | AlmaLinux:8 | All versions | 32:9.16.23-0.14.el8_8.1.alma |
| `bind` | AlmaLinux:9 | All versions | 32:9.16.23-11.el9_2.1 |
| `bind-chroot` | AlmaLinux:9 | All versions | 32:9.16.23-11.el9_2.1 |
| `bind-devel` | AlmaLinux:9 | All versions | 32:9.16.23-11.el9_2.1 |
| `bind-dnssec-doc` | AlmaLinux:9 | All versions | 32:9.16.23-11.el9_2.1 |
| `bind-dnssec-utils` | AlmaLinux:9 | All versions | 32:9.16.23-11.el9_2.1 |
| `bind-doc` | AlmaLinux:9 | All versions | 32:9.16.23-11.el9_2.1 |
| `bind-libs` | AlmaLinux:9 | All versions | 32:9.16.23-11.el9_2.1 |
| `bind-license` | AlmaLinux:9 | All versions | 32:9.16.23-11.el9_2.1 |
| `bind-utils` | AlmaLinux:9 | All versions | 32:9.16.23-11.el9_2.1 |
| `python3-bind` | AlmaLinux:9 | All versions | 32:9.16.23-11.el9_2.1 |
| `bind` | Red Hat:enterprise_linux:7::client | All versions | 32:9.11.4-26.P2.el7_9.14 |
| `bind-chroot` | Red Hat:enterprise_linux:7::client | All versions | 32:9.11.4-26.P2.el7_9.14 |
| `bind-debuginfo` | Red Hat:enterprise_linux:7::client | All versions | 32:9.11.4-26.P2.el7_9.14 |
| `bind-devel` | Red Hat:enterprise_linux:7::client | All versions | 32:9.11.4-26.P2.el7_9.14 |

Products: Debian Debian Linux, Fedoraproject Fedora, Isc Bind, Netapp Active Iq Unified Manager, Netapp H300s Firmware, Netapp H410c Firmware, Netapp H410s Firmware, Netapp H500s Firmware, Netapp H700s Firmware.

## How do I fix CVE-2023-2828?

Upgrade to a fixed version.

## Is CVE-2023-2828 being exploited?

There is no known exploitation of CVE-2023-2828 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-2828 and fix it if it is affected.

What it is: CVE-2023-2828 is a high-severity denial of service vulnerability in Debian Debian Linux, published on 21 Jun 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-2023-2828 in the wild and no public exploit code.

Affected product: Debian Debian Linux. 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-2023-2828/ (Markdown: https://insights.sbomify.com/CVE-2023-2828/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-2828
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-2828
- OSV: https://osv.dev/vulnerability/CVE-2023-2828

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-2828/
Summaries are generated and may contain mistakes; the official description above is the record.