Security readout for executives and security teams
Plain-English summary
CVE-2019-7303 is a sandbox escape weakness in Canonical snapd before 2.37.4. A confined snap could push characters into a user’s terminal on a 64-bit host, creating a local integrity and confidentiality risk. It requires local privileges and user interaction, so urgency is moderate unless untrusted snaps or shared systems are common.
Executive priority
Treat this as a moderate local containment failure. It is less urgent than remote code execution, but important for shared Linux environments, developer workstations, and systems where users may run third-party snaps. Patch during the next security maintenance window, faster for high-risk multi-user hosts.
Technical view
The issue is in snapd seccomp filtering for ioctl handling. Rules matched 64-bit ioctl command values, while the Linux kernel used only the lower 32 bits to select the ioctl operation. This allowed a strict mode snap to bypass the intended TIOCSTI restriction and inject terminal input on 64-bit systems.
Likely exposure
Exposure is likely on 64-bit Linux systems running Canonical snapd versions before 2.37.4, especially shared workstations, developer hosts, or environments allowing untrusted snaps. Systems without snapd or already updated to fixed vendor packages are not indicated as affected by the provided sources.
Exploitation context
The CVE is not listed as KEV in the provided bundle, so active exploitation is not established. A public Exploit-DB reference exists, indicating public exploit information was available. The vulnerability remains local and requires privileges plus user interaction, limiting broad remote attack potential.
Researcher notes
Key evidence is the CVE description and Ubuntu advisory: the bug depends on 64-bit ioctl filtering semantics versus kernel lower-32-bit ioctl selection. The provided sources do not establish active exploitation, affected distributions beyond Canonical snapd, or mitigations other than updating via vendor guidance.
Mitigation direction
- Update Canonical snapd to version 2.37.4 or later.
- Apply Ubuntu vendor updates referenced in USN-3917-1.
- Prioritize shared hosts and systems allowing untrusted snap installation.
- Review vendor guidance for distribution-specific fixed package versions.
Validation and detection
- Inventory hosts with snapd installed and record package versions.
- Confirm affected systems are updated beyond snapd 2.37.4.
- Check whether local users can install or run untrusted strict mode snaps.
- Verify Ubuntu security updates from USN-3917-1 are applied.
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-628: Exact CWE lookup
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Open ATT&CK lookupCVE-2019-7303 mapping review
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Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.7 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L
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:L/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L1.53.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
5.7MediumVector: CVSS:3.0/AV:L/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L
Source materials
- CVE List V5 sourceCVE List V5
- https://usn.ubuntu.com/3917-1/CVE reference · x_refsource_MISC
- https://www.exploit-db.com/exploits/46594CVE reference · x_refsource_MISC
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.
Function Call with Incorrectly Specified Arguments
Function Call with Incorrectly Specified Arguments represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.