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CVE-2020-3118

Cisco IOS XR Software Cisco Discovery Protocol Format String Vulnerability

Exploited in the wild. In CISA KEV since 2021‑11‑03. Fixed versions are out.

CVSS 3.18.8HighEPSS percentile96th12% chance in 30 daysCISA KEVListedsince 2021-11-03, due 2022-05-03
Public exploit: 1 sourceFix2 products2 fixed builds listed below

Published Updated Sources: CVE.org, NVD, BDU

NVD CVE.org

What to do

Find your product and version, then upgrade to the build on the right.

  • Cisco IOS XR SoftwareAffected: ≥ unspecified, < 6.6.3Upgrade to: 6.6.3Stated by: CVE record
  • Cisco Ios XrAffected: ≥ 6.6.0, < 6.6.12Upgrade to: 6.6.12Stated by: NVD

Versions as the sources state them. Full version matrix after sign-in

Check it yourselfA free OpenVAS check exists for this CVE. Run it against your hosts.Is your organisation exposed?Request an assessment to establish which checks fit your systems.

Coverage timeline

0 publishers

  1. Added to CISA KEV catalog

    ·CISA KEV

Sourced from public security reporting — each date is when it was published, not when it happened.

What it is

From the CVE record

A vulnerability in the Cisco Discovery Protocol implementation for Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to execute arbitrary code or cause a reload on an affected device. The vulnerability is due to improper validation of string input from certain fields in Cisco Discovery Protocol messages. An attacker could exploit this vulnerability by sending a malicious Cisco Discovery Protocol packet to an affected device. A successful exploit could allow the attacker to cause a stack overflow, which could allow the attacker to execute arbitrary code with administrative privileges on an affected device. Cisco Discovery Protocol is a Layer 2 protocol. To exploit this vulnerability, an attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent).

In plain language

No plain-language summary for this CVE yet.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS96th
Public exploit
CISA KEV
CISA KEV

Listed as exploited in the wild since 2021-11-03.

US federal agencies must remediate by 2022-05-03.

Apply updates per vendor instructions.
Public exploits

1 source with a proof of concept or module.

Exploit links, PoCs and Metasploit modules after sign-in
EPSS

12% chance of exploitation activity in the next 30 days, which ranks it in the 96th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Attention now

Rising.

Lifecycle

The patch came 129 days before any public exploit.

  1. OpenVAS check added
  2. EPSS band changelow → moderate
  3. Public exploit / PoCsource: packetstorm
  4. Patch availablerecord updated
  5. Added to CISA KEV
  6. Publishedweakness classified, att&ck mapped

Affected products

Technical detail

CVSS 3.1 vector

Open in the CVSS calculator

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Scored 8.8 by NVD.

How it is reached

  • Attack Vector AdjacentRequires access to the local network (e.g. same Wi-Fi, Bluetooth)
  • Attack Complexity LowNo special conditions — the attack can be reliably reproduced
  • Privileges Required NoneNo authentication required — anyone can exploit this
  • User Interaction NoneNo user interaction needed — fully automated exploitation

Scope

  • Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

  • Confidentiality HighTotal information disclosure — all data in the component is compromised
  • Integrity HighTotal loss of integrity — attacker can modify any data in the component
  • Availability HighTotal denial of service — the component is completely unavailable

Weaknesses

ATT&CK techniques

Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.

Sources

References in the record

And 2 more references. See all after sign-in

Watch the software you run.

My Stack ranks new CVEs for your products by real-world exploitation, so the next exploited one reaches you without reading every advisory.

We'll flag the next CVE, public exploit or patch for Ios Xr, not every advisory. This one: actively exploited.