November 13, 2026 Follow Egret
CVE-2020-3161 · CVE record: PUBLISHED

Cisco IP Phones Web Server Remote Code Execution and Denial of Service Vulnerability

Cisco Cisco IP phone

A vulnerability in the web server for Cisco IP Phones could allow an unauthenticated, remote attacker to execute code with root privileges or cause a reload of an affected IP phone, resulting in a denial of service (DoS) condition. The vulnerability is due to a lack of proper input validation of HTTP requests. An attacker could exploit this vulnerability by sending a crafted HTTP request to the web server of a targeted device. A successful exploit could allow the attacker to remotely execute code with root privileges or cause a reload of an affected IP phone, resulting in a DoS condition.

Exploitation evidence

Known exploited · CISA KEV listed

Added 2021-11-03. Ransomware campaign use: Unknown.

CISA required action: Apply updates per vendor instructions.

CISA due date: 2022-05-03. This is the catalog’s deadline, not an assessment of your organization’s exposure.

KEV checked 13 Nov 2026, 00:20 Jerusalem · Original catalog ↗

Reported products and versions

Cisco / Cisco IP phone

Default status: Not specified

  • affected: n/a

Fixes and workarounds

No explicit solution text in the downloaded CVE record. Consult the vendor advisory; unaffected version ranges are shown above as reported, not inferred as a patch recommendation.

Sources and related reporting

CVE Program record ↗ · Download tracked evidence as JSON

Observed change timeline

History begins when Egret first downloads each source. It is not the complete upstream CVE history.

12 Nov 2026, 18:20 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-12",
  "epss": 0.83855,
  "percentile": 0.99695
}
10 Nov 2026, 18:20 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-10",
  "epss": 0.83855,
  "percentile": 0.99693
}
09 Nov 2026, 18:20 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-09",
  "epss": 0.83855,
  "percentile": 0.99692
}
08 Nov 2026, 18:20 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-08",
  "epss": 0.83855,
  "percentile": 0.99692
}
07 Nov 2026, 18:20 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-07",
  "epss": 0.83855,
  "percentile": 0.99692
}
06 Nov 2026, 18:20 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-06",
  "epss": 0.83855,
  "percentile": 0.99692
}
06 Nov 2026, 06:20 Jerusalem · CVE Program record changed

Stored CNA snapshot at this observation.

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05 Nov 2026, 18:20 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-05",
  "epss": 0.83855,
  "percentile": 0.99691
}
04 Nov 2026, 18:20 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-04",
  "epss": 0.83855,
  "percentile": 0.99691
}
03 Nov 2026, 18:20 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-03",
  "epss": 0.83855,
  "percentile": 0.9969
}
03 Nov 2026, 02:22 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-02",
  "epss": 0.83855,
  "percentile": 0.9969
}
03 Nov 2026, 02:22 Jerusalem · CISA KEV status changed

Stored KEV snapshot at this observation.

{
  "cveID": "CVE-2020-3161",
  "cwes": [
    "CWE-20"
  ],
  "dateAdded": "2021-11-03",
  "dueDate": "2022-05-03",
  "forensicTriage": "No",
  "knownRansomwareCampaignUse": "Unknown",
  "notes": "https://nvd.nist.gov/vuln/detail/CVE-2020-3161",
  "product": "Cisco IP Phones",
  "requiredAction": "Apply updates per vendor instructions.",
  "shortDescription": "Cisco IP Phones contain an improper input validation vulnerability for HTTP requests. Exploitation could allow an attacker to execute code remotely with root privileges or cause a denial-of-service (DoS) condition.",
  "vendorProject": "Cisco",
  "vulnerabilityName": "Cisco IP Phones Web Server Remote Code Execution and Denial-of-Service Vulnerability"
}
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