Security readout for executives and security teams
Plain-English summary
This flaw can let an unauthenticated remote actor crash and reload affected Cisco IOS or IOS XE devices by abusing SIP message handling. The business impact is service disruption, especially where those devices support voice or network edge availability.
Executive priority
Prioritize remediation where affected devices support voice, branch connectivity, or edge availability. The risk is downtime rather than data theft, but remote unauthenticated triggering makes exposed systems operationally important.
Technical view
CVE-2020-3226 is a SIP library input-validation flaw in Cisco IOS and IOS XE. Insufficient sanity checks on received SIP messages can trigger device reload, causing denial of service. CVSS v3.0 is 8.6 with network access, low complexity, no privileges, and high availability impact.
Likely exposure
Exposure is most likely on Cisco IOS or IOS XE devices running affected releases and processing SIP traffic. The bundle specifically lists Cisco IOS 15.0(2)SG11a, while the Cisco advisory should be used to confirm broader affected software.
Exploitation context
The provided sources describe unauthenticated remote exploitation by crafted SIP messages, but do not show active exploitation. The CVE is not marked as KEV in the supplied bundle, so treat exploitation status as unconfirmed from these sources.
Researcher notes
The source bundle supports CWE-20 input validation weakness, high availability impact, and unauthenticated remote DoS. It does not provide exploit maturity, observed attacks, or detailed fixed-release data, so vendor advisory review is required for precise remediation.
Mitigation direction
- Review Cisco advisory for affected and fixed releases before changing production devices.
- Prioritize remediation for SIP-exposed Cisco IOS and IOS XE devices.
- Restrict SIP traffic to trusted peers where operationally feasible.
- Monitor for unexpected reloads affecting devices that process SIP.
- Apply vendor-recommended fixes or mitigations from Cisco guidance.
Validation and detection
- Inventory Cisco IOS and IOS XE devices and record exact software versions.
- Identify devices configured to process SIP traffic from untrusted networks.
- Compare versions against Cisco advisory affected and fixed software guidance.
- Review device logs for unexplained reloads near SIP traffic events.
- Confirm access controls limit SIP exposure to expected sources.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-20: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2020-3226 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.6 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H3.94Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
8.6HighVector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20200603 Cisco IOS and IOS XE Software Session Initiation Protocol Denial of Service VulnerabilityCVE reference · vendor-advisory, x_refsource_CISCO
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Input Validation
Improper Input Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.