Security readout for executives and security teams
Plain-English summary
CVE-2021-1048 is an Android kernel memory corruption flaw. An attacker who already has local code execution, such as through an app context, could elevate privileges without user interaction. CISA lists it in KEV, so treat it as known exploited.
Executive priority
High priority for Android fleets, especially unmanaged, exposed, or unsupported devices. KEV status means exploitation has been observed, and successful abuse can give an attacker deeper control over a compromised device.
Technical view
The flaw is a use-after-free in ep_loop_check_proc in Linux eventpoll code used by the Android kernel. The CVSS vector is local, low complexity, low privileges, no user interaction, with high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is most relevant to Android devices running affected Android kernel builds that have not received the relevant Android or OEM kernel security update. The source bundle does not identify specific device models or Android release numbers beyond Android kernel.
Exploitation context
Active exploitation is supported by CISA KEV listing for CVE-2021-1048. The vulnerability is local privilege escalation, not a network-entry vulnerability based on the supplied CVSS vector and Android description.
Researcher notes
Evidence supports Android kernel local privilege escalation through a CWE-416 use-after-free in eventpoll.c. The bundle does not provide exploit mechanics, affected model lists, or detailed patch commits. Validate using Android bulletin and OEM-specific advisories rather than assuming uniform device coverage.
Mitigation direction
- Apply Android or OEM security updates that address CVE-2021-1048.
- Check device vendor guidance for model-specific kernel patch availability.
- Prioritize unsupported Android devices for replacement, isolation, or compensating controls.
- Limit untrusted app installation to reduce local attack opportunities.
- Track remediation against CISA KEV urgency expectations.
Validation and detection
- Inventory Android devices and record security patch levels.
- Confirm OEM bulletins or update notes include CVE-2021-1048 remediation.
- Identify devices without an available vendor update path.
- Review mobile threat detections for suspicious local privilege escalation behavior.
- Document exceptions for unsupported devices and compensating controls.
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-416: 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-2021-1048 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
- 7.8 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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.
CISA KEV status
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:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://source.android.com/security/bulletin/2021-11-01CVE reference · x_refsource_MISC
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-1048CVE reference · government-resource
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.
Use After Free
Use After Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.