# CVE-2017-3864: Denial of service in Cisco IOS and IOS XE

> Remote attackers can cause a device reload and denial of service by sending crafted DHCP packets to Cisco IOS devices configured as DHCP clients.

- **Severity:** High 8.6 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/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:** No
- **Published:** 22 Mar 2017
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-qj55-f9h6-mf7m

## What is CVE-2017-3864?

CVE-2017-3864 is a high-severity denial of service vulnerability in Cisco Ios, published on 22 Mar 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the DHCP client implementation of Cisco IOS (12.2, 12.4, and 15.0 through 15.6) and Cisco IOS XE (3.3 through 3.7) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability occurs during the parsing of a crafted DHCP packet. An attacker could exploit this vulnerability by sending crafted DHCP packets to an affected device that is configured as a DHCP client. A successful exploit could allow the attacker to cause a reload of an affected device, resulting in a DoS condition. This vulnerability affects Cisco devices that are running a vulnerable release of Cisco IOS or IOS XE Software and using a specific DHCP client configuration. Cisco Bug IDs: CSCuu43892.

Weakness: CWE-399

## Which versions are affected by CVE-2017-3864?

It affects 2 products.


Products: Cisco Ios, Cisco Ios Xe.

## How do I fix CVE-2017-3864?

No fix has been published for CVE-2017-3864 yet. Limit exposure of the affected software until one is available.

## Is CVE-2017-3864 being exploited?

There is no known exploitation of CVE-2017-3864 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Ios

- [CVE-2017-12240](https://insights.sbomify.com/CVE-2017-12240/): Cisco IOS and IOS XE Software DHCP Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2017-3881](https://insights.sbomify.com/CVE-2017-3881/): Cisco IOS and IOS XE Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2018-0167](https://insights.sbomify.com/CVE-2018-0167/): Cisco IOS, XR, and XE Software Buffer Overflow (high 8.8, exploited in the wild)
- [CVE-2017-6736](https://insights.sbomify.com/CVE-2017-6736/): Cisco IOS and IOS XE Software SNMP Remote Code Execution (high 8.8, exploited in the wild)
- [CVE-2017-6737](https://insights.sbomify.com/CVE-2017-6737/): Cisco IOS and IOS XE Software SNMP Remote Code Execution (high 8.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-3864 and fix it if it is affected.

What it is: CVE-2017-3864 is a high-severity denial of service vulnerability in Cisco Ios, published on 22 Mar 2017. 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-2017-3864 in the wild and no public exploit code.

Affected product: Cisco Ios. 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-2017-3864/ (Markdown: https://insights.sbomify.com/CVE-2017-3864/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-3864
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-3864
- OSV: https://osv.dev/vulnerability/CVE-2017-3864

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From sbomify Insights: https://insights.sbomify.com/CVE-2017-3864/
Summaries are generated and may contain mistakes; the official description above is the record.