Security readout for executives and security teams
Plain-English summary
This vulnerability can let an unauthenticated remote attacker crash and reload an affected Cisco IOS or IOS XE device by sending malicious SIP traffic. The business impact is service interruption, not data theft. Devices handling voice or SIP-related traffic are the main concern.
Executive priority
Treat this as high priority for voice, edge, or routing infrastructure where device reloads could disrupt business operations. Prioritize externally reachable or critical-path Cisco devices first.
Technical view
CVE-2019-12654 affects Cisco IOS and IOS XE common SIP library logic. Insufficient sanity checks on an internal data structure can lead to a NULL pointer dereference, crashing the iosd process and triggering device reload. CVSS v3.0 is 8.6 with network attack vector, no privileges, no user interaction, and high availability impact.
Likely exposure
Exposure is most likely where Cisco IOS or IOS XE devices process SIP traffic, especially internet-facing or untrusted-network reachable SIP services. The source bundle names Cisco IOS 15.0(1)XA2 and points to Cisco’s advisory for full affected-release details.
Exploitation context
The provided sources describe unauthenticated remote denial of service with low attack complexity. The CVE is not marked as KEV, and the bundle provides no evidence of active exploitation. Impact is availability loss through device reload.
Researcher notes
The bundle supports DoS impact through SIP message handling and NULL pointer dereference. It does not provide complete affected-version coverage, patch version detail, or active exploitation evidence, so validation should be anchored to Cisco’s advisory.
Mitigation direction
- Review Cisco’s advisory for affected releases and fixed software guidance.
- Prioritize upgrades for SIP-exposed Cisco IOS and IOS XE devices.
- Restrict SIP reachability to trusted networks where operationally possible.
- Monitor for unexpected reloads or iosd crashes on potentially affected devices.
Validation and detection
- Inventory Cisco IOS and IOS XE devices and software versions.
- Identify devices with SIP processing enabled or reachable from untrusted networks.
- Compare discovered versions against Cisco’s advisory.
- Review logs for reloads or iosd crashes correlated with SIP traffic.
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
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CWE-476: Exact CWE lookup
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Open ATT&CK lookupCVE-2019-12654 mapping review
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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
- 20190925 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.
NULL Pointer Dereference
NULL Pointer Dereference represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.