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CVE Record

CVE-2022-50077: apparmor: fix reference count leak in aa_pivotroot()

In the Linux kernel, the following vulnerability has been resolved: apparmor: fix reference count leak in aa_pivotroot() The aa_pivotroot() function has a reference counting bug in a specific path. When aa_replace_current_label() returns on success, the function forgets to decrement the reference count of “target”, which is increased earlier by build_pivotroot(), causing a reference leak. Fix it by decreasing the refcount of “target” in that path.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2022-50077 is a Linux kernel AppArmor bug where a successful pivot-root label replacement can leave a reference count unreleased. The provided sources describe a resource leak, not direct code execution or privilege escalation. Business urgency is currently unclear because no CVSS score, CWE, or exploitation evidence is provided.

Executive priority

Handle through normal kernel patch governance unless an affected AppArmor-heavy environment is confirmed. Escalate priority for shared infrastructure, container platforms, or systems with delayed kernel maintenance, because source evidence does not establish active exploitation or high impact.

Technical view

The issue is in aa_pivotroot(). build_pivotroot() increments the target label reference count, but one success path after aa_replace_current_label() failed to decrement it. Stable kernel fixes add the missing refcount drop. The source bundle lists Linux kernels as affected, with stable commit references for remediation.

Likely exposure

Exposure appears limited to Linux systems running affected kernel versions where AppArmor pivot-root handling is reachable. Containerized or sandboxed workloads using AppArmor may be more relevant, but the provided sources do not prove a practical attack path.

Exploitation context

The bundle marks KEV as false and provides no cited evidence of active exploitation, public exploit code, or weaponized use. The impact is described only as a reference count leak, so exploitability and operational impact remain insufficiently evidenced.

Researcher notes

The key uncertainty is impact. The record describes a missing refcount decrement in aa_pivotroot(), but does not provide CVSS, CWE, crash evidence, memory exhaustion details, or exploit preconditions. Research should focus on reachable call paths and whether repeated triggering can create denial-of-service conditions.

Mitigation direction

  • Apply vendor kernel updates containing the referenced stable fixes.
  • Prioritize Linux hosts that use AppArmor for container or sandbox confinement.
  • Check distribution advisories for backported fixes before relying on version strings.
  • Monitor CVE and vendor updates for severity or exploitability changes.

Validation and detection

  • Inventory Linux kernel versions across servers, images, and appliances.
  • Confirm whether AppArmor is enabled on potentially affected systems.
  • Map installed kernels to vendor advisories or referenced stable commits.
  • Verify patched kernels are running after reboot, not merely installed.
Prepared
Confidence
medium
Sources
9

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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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CVE-2022-50077 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

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.

0CVSS vectors
3Timeline events
0ADP providers
8Source links

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux2ea3ffb7782a84da33a8382f13ebd016da50079b, 2ea3ffb7782a84da33a8382f13ebd016da50079b, 2ea3ffb7782a84da33a8382f13ebd016da50079b, 2ea3ffb7782a84da33a8382f13ebd016da50079b, 2ea3ffb7782a84da33a8382f13ebd016da50079b, 2ea3ffb7782a84da33a8382f13ebd016da50079b, 2ea3ffb7782a84da33a8382f13ebd016da50079bunaffected
LinuxLinux4.14, 0, 4.14.291, 4.19.256, 5.4.211, 5.10.138, 5.15.63, 5.19.4, 6.0affected
Weakness

CWE details

No CWE listed

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