# CVE-2024-20373: Cisco IOS and Cisco IOS XE SNMP Extended ACL Bypass Vulnerability

> Attackers can bypass SNMP access controls on Cisco IOS XE devices configured with unsupported extended ACLs, allowing unauthorized SNMP polling.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 15 Nov 2024
- **Updated:** 15 Nov 2024
- **Also known as:** GHSA-3xmf-m2fg-h94r

## What is CVE-2024-20373?

CVE-2024-20373 is a medium-severity vulnerability in Cisco IOS XE Catalyst SD-WAN, published on 15 Nov 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the implementation of the Simple Network Management Protocol (SNMP) IPv4 access control list (ACL) feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to perform SNMP polling of an affected device, even if it is configured to deny SNMP traffic. 

This vulnerability exists because Cisco IOS Software and Cisco IOS XE Software do not support extended IPv4 ACLs for SNMP, but they do allow administrators to configure extended named IPv4 ACLs that are attached to the SNMP server configuration without a warning message. This can result in no ACL being applied to the SNMP listening process. An attacker could exploit this vulnerability by performing SNMP polling of an affected device. A successful exploit could allow the attacker to perform SNMP operations that should be denied. The attacker has no control of the SNMP ACL configuration and would still need a valid SNMP version 2c (SNMPv2c) community string or SNMP version 3 (SNMPv3) user credentials.
SNMP with IPv6 ACL configurations is not affected.
For more information, see the  section of this advisory.

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2024-20373?

It affects 1 product.


Products: Cisco Ios Xe Sd-Wan.

## How do I fix CVE-2024-20373?

No fix has been published for CVE-2024-20373 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-20373 being exploited?

There is no known exploitation of CVE-2024-20373 in the wild and no public exploit code.

## Other vulnerabilities in Cisco IOS XE Catalyst SD-WAN

- [CVE-2021-34727](https://insights.sbomify.com/CVE-2021-34727/): Cisco IOS XE SD-WAN Software Buffer Overflow Vulnerability (critical 9.8)
- [CVE-2020-3375](https://insights.sbomify.com/CVE-2020-3375/): Cisco SD-WAN Solution Software Buffer Overflow Vulnerability (critical 9.8)
- [CVE-2021-1305](https://insights.sbomify.com/CVE-2021-1305/): Cisco SD-WAN vManage Authorization Bypass Vulnerabilities (high 8.8)
- [CVE-2023-20035](https://insights.sbomify.com/CVE-2023-20035/): Cisco IOS XE SD-WAN Software Command Injection Vulnerability (high 7.8)
- [CVE-2020-3216](https://insights.sbomify.com/CVE-2020-3216/): Cisco IOS XE SD-WAN Software Authentication Bypass Vulnerability (medium 6.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-20373 and fix it if it is affected.

What it is: CVE-2024-20373 is a medium-severity vulnerability in Cisco IOS XE Catalyst SD-WAN, published on 15 Nov 2024. 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-2024-20373 in the wild and no public exploit code.

Affected product: Cisco IOS XE Catalyst SD-WAN. 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-2024-20373/ (Markdown: https://insights.sbomify.com/CVE-2024-20373/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-20373
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-20373
- OSV: https://osv.dev/vulnerability/CVE-2024-20373

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-20373/
Summaries are generated and may contain mistakes; the official description above is the record.