# CVE-2017-3881: Cisco IOS and IOS XE Remote Code Execution

> Unauthenticated remote attackers can execute arbitrary code or cause device reloads via malformed Telnet options in Cisco IOS and IOS XE.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Yes, since 25 Mar 2022 (CISA KEV)
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 17 Mar 2017
- **Updated:** 12 Jan 2026
- **Also known as:** GHSA-g37w-qg7v-7fjq

## What is CVE-2017-3881?

CVE-2017-3881 is a critical code injection vulnerability in Cisco Ios, published on 17 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 Cisco Cluster Management Protocol (CMP) processing code in Cisco IOS and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a reload of an affected device or remotely execute code with elevated privileges. The Cluster Management Protocol utilizes Telnet internally as a signaling and command protocol between cluster members. The vulnerability is due to the combination of two factors: (1) the failure to restrict the use of CMP-specific Telnet options only to internal, local communications between cluster members and instead accept and process such options over any Telnet connection to an affected device; and (2) the incorrect processing of malformed CMP-specific Telnet options. An attacker could exploit this vulnerability by sending malformed CMP-specific Telnet options while establishing a Telnet session with an affected Cisco device configured to accept Telnet connections. An exploit could allow an attacker to execute arbitrary code and obtain full control of the device or cause a reload of the affected device. This affects Catalyst switches, Embedded Service 2020 switches, Enhanced Layer 2 EtherSwitch Service Module, Enhanced Layer 2/3 EtherSwitch Service Module, Gigabit Ethernet Switch Module (CGESM) for HP, IE Industrial Ethernet switches, ME 4924-10GE switch, RF Gateway 10, and SM-X Layer 2/3 EtherSwitch Service Module. Cisco Bug IDs: CSCvd48893.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2017-3881?

It affects 2 products.


Products: Cisco Ios, Cisco Ios Xe.

## How do I fix CVE-2017-3881?

No fix has been published for CVE-2017-3881 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 15 Apr 2022.

## Is CVE-2017-3881 being exploited?

Yes. Attackers have exploited CVE-2017-3881 in the wild since at least 25 Mar 2022.

Public exploit code:

- CVE-2017-3881 Cisco Catalyst Remote Code Execution PoC (github_poc): https://github.com/artkond/cisco-rce
- https://github.com/homjxi0e/CVE-2017-3881-exploit-cisco- (github_poc): https://github.com/homjxi0e/CVE-2017-3881-exploit-cisco-
- credit to artkond (github_poc): https://github.com/1337g/CVE-2017-3881
- Cisco Catalyst Remote Code Execution PoC (github_poc): https://github.com/mzakyz666/PoC-CVE-2017-3881
- Cisco IOS Telnet Denial of Service (metasploit)
- Cisco Catalyst 2960 IOS 12.2(55)SE11 - 'ROCEM' Remote Code Execution (exploitdb)

## 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-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)
- [CVE-2017-6738](https://insights.sbomify.com/CVE-2017-6738/): 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-2017-3881 and fix it if it is affected.

What it is: CVE-2017-3881 is a critical code injection vulnerability in Cisco Ios, published on 17 Mar 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2017-3881 in the wild since at least 25 Mar 2022.

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-2017-3881/ (Markdown: https://insights.sbomify.com/CVE-2017-3881/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-3881
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-3881
- OSV: https://osv.dev/vulnerability/CVE-2017-3881

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From sbomify Insights: https://insights.sbomify.com/CVE-2017-3881/
Summaries are generated and may contain mistakes; the official description above is the record.