# CVE-2021-3480: Null dereference in slapi-nis

> An unauthenticated attacker can crash the 389-ds-base directory server via a NULL pointer dereference in the slapi-nis plugin.

- **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:** 20 May 2021
- **Updated:** 3 Aug 2024
- **Also known as:** ALSA-2021:1983, DEBIAN-CVE-2021-3480, GHSA-7c98-4wpw-92jq, RHSA-2021:1983, RHSA-2021:2026, RHSA-2021:2027, RHSA-2021:2032, RLSA-2021:1983, UBUNTU-CVE-2021-3480

## What is CVE-2021-3480?

CVE-2021-3480 is a high-severity vulnerability in Fedoraproject Fedora, published on 20 May 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A flaw was found in slapi-nis in versions before 0.56.7. A NULL pointer dereference during the parsing of the Binding DN could allow an unauthenticated attacker to crash the 389-ds-base directory server. The highest threat from this vulnerability is to system availability.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2021-3480?

It affects 2 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `bind-dyndb-ldap` | AlmaLinux:8 | All versions | 11.6-2.module_el8.5.0+2603+92118e57 |
| `custodia` | AlmaLinux:8 | All versions | 0.6.0-3.module_el8.5.0+2603+92118e57 |
| `custodia` | AlmaLinux:8 | All versions | 0.6.0-3.module_el8.6.0+2881+2f24dc92 |
| `opendnssec` | AlmaLinux:8 | All versions | 2.1.7-1.module_el8.5.0+2603+92118e57 |
| `opendnssec` | AlmaLinux:8 | All versions | 2.1.7-1.module_el8.6.0+2881+2f24dc92 |
| `python3-custodia` | AlmaLinux:8 | All versions | 0.6.0-3.module_el8.5.0+2603+92118e57 |
| `python3-custodia` | AlmaLinux:8 | All versions | 0.6.0-3.module_el8.6.0+2881+2f24dc92 |
| `python3-jwcrypto` | AlmaLinux:8 | All versions | 0.5.0-1.module_el8.5.0+2603+92118e57 |
| `python3-jwcrypto` | AlmaLinux:8 | All versions | 0.5.0-1.module_el8.6.0+2737+7e73ea90 |
| `python3-jwcrypto` | AlmaLinux:8 | All versions | 0.5.0-1.module_el8.6.0+2881+2f24dc92 |
| `python3-kdcproxy` | AlmaLinux:8 | All versions | 0.4-5.module_el8.5.0+2603+92118e57 |
| `python3-kdcproxy` | AlmaLinux:8 | All versions | 0.4-5.module_el8.6.0+2881+2f24dc92 |
| `python3-pyusb` | AlmaLinux:8 | All versions | 1.0.0-9.module_el8.5.0+2603+92118e57 |
| `python3-pyusb` | AlmaLinux:8 | All versions | 1.0.0-9.module_el8.6.0+2737+7e73ea90 |
| `python3-pyusb` | AlmaLinux:8 | All versions | 1.0.0-9.module_el8.6.0+2881+2f24dc92 |
| `python3-qrcode` | AlmaLinux:8 | All versions | 5.1-12.module_el8.5.0+2603+92118e57 |
| `python3-qrcode` | AlmaLinux:8 | All versions | 5.1-12.module_el8.6.0+2737+7e73ea90 |
| `python3-qrcode` | AlmaLinux:8 | All versions | 5.1-12.module_el8.6.0+2881+2f24dc92 |
| `python3-qrcode-core` | AlmaLinux:8 | All versions | 5.1-12.module_el8.5.0+2603+92118e57 |
| `python3-qrcode-core` | AlmaLinux:8 | All versions | 5.1-12.module_el8.6.0+2737+7e73ea90 |
| `python3-qrcode-core` | AlmaLinux:8 | All versions | 5.1-12.module_el8.6.0+2881+2f24dc92 |
| `python3-yubico` | AlmaLinux:8 | All versions | 1.3.2-9.module_el8.5.0+2603+92118e57 |
| `python3-yubico` | AlmaLinux:8 | All versions | 1.3.2-9.module_el8.6.0+2737+7e73ea90 |
| `python3-yubico` | AlmaLinux:8 | All versions | 1.3.2-9.module_el8.6.0+2881+2f24dc92 |
| `softhsm` | AlmaLinux:8 | All versions | 2.6.0-5.module_el8.5.0+2603+92118e57 |
| `softhsm` | AlmaLinux:8 | All versions | 2.6.0-5.module_el8.6.0+2881+2f24dc92 |
| `softhsm-devel` | AlmaLinux:8 | All versions | 2.6.0-5.module_el8.5.0+2603+92118e57 |
| `softhsm-devel` | AlmaLinux:8 | All versions | 2.6.0-5.module_el8.6.0+2881+2f24dc92 |
| `slapi-nis` | Red Hat:enterprise_linux:7::client | All versions | 0:0.56.5-4.el7_9 |
| `slapi-nis-debuginfo` | Red Hat:enterprise_linux:7::client | All versions | 0:0.56.5-4.el7_9 |
| `slapi-nis` | Red Hat:enterprise_linux:7::computenode | All versions | 0:0.56.5-4.el7_9 |
| `slapi-nis-debuginfo` | Red Hat:enterprise_linux:7::computenode | All versions | 0:0.56.5-4.el7_9 |
| `slapi-nis` | Red Hat:enterprise_linux:7::server | All versions | 0:0.56.5-4.el7_9 |
| `slapi-nis-debuginfo` | Red Hat:enterprise_linux:7::server | All versions | 0:0.56.5-4.el7_9 |
| `slapi-nis` | Red Hat:enterprise_linux:7::workstation | All versions | 0:0.56.5-4.el7_9 |
| `slapi-nis-debuginfo` | Red Hat:enterprise_linux:7::workstation | All versions | 0:0.56.5-4.el7_9 |
| `bind-dyndb-ldap` | Red Hat:enterprise_linux:8::appstream | All versions | 0:11.6-2.module+el8.4.0+9328+4ec4e316 |
| `bind-dyndb-ldap-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:11.6-2.module+el8.4.0+9328+4ec4e316 |
| `bind-dyndb-ldap-debugsource` | Red Hat:enterprise_linux:8::appstream | All versions | 0:11.6-2.module+el8.4.0+9328+4ec4e316 |
| `custodia` | Red Hat:enterprise_linux:8::appstream | All versions | 0:0.6.0-3.module+el8.1.0+4098+f286395e |

Products: Fedoraproject Fedora, Slapi-Nis Project Slapi-Nis.

## How do I fix CVE-2021-3480?

Upgrade to a fixed version.

## Is CVE-2021-3480 being exploited?

There is no known exploitation of CVE-2021-3480 in the wild and no public exploit code.

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- [CVE-2024-4947](https://insights.sbomify.com/CVE-2024-4947/): Google Chromium V8 Type Confusion (critical 9.6, exploited in the wild)
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## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-3480 and fix it if it is affected.

What it is: CVE-2021-3480 is a high-severity vulnerability in Fedoraproject Fedora, published on 20 May 2021. 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-2021-3480 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-2021-3480/ (Markdown: https://insights.sbomify.com/CVE-2021-3480/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-3480
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-3480
- OSV: https://osv.dev/vulnerability/CVE-2021-3480

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-3480/
Summaries are generated and may contain mistakes; the official description above is the record.