Security readout for executives and security teams
Plain-English summary
CVE-2020-36780 is a Linux kernel availability issue in the sprd I2C driver. When a runtime power-management resume call fails, the driver can leave a reference count unbalanced. Over time or under specific failure conditions, this can contribute to denial of service. The cited CVSS score is 4.7, and no source says it is actively exploited.
Executive priority
Handle through normal kernel patch management unless the affected driver is present on systems exposed to untrusted local users or workloads. Business urgency is moderate because impact is denial of service only, but kernel reliability defects can matter on embedded, mobile, or appliance-style platforms.
Technical view
The flaw is a PM runtime reference leak in sprd_i2c_master_xfer() and sprd_i2c_remove(). pm_runtime_get_sync increments the usage counter even on failure; missing the corresponding put operation leaves the counter unbalanced. Stable fixes replace it with pm_runtime_resume_and_get. Impact is availability only, local attack vector, high complexity, and low privileges required.
Likely exposure
Exposure appears limited to Linux systems running affected kernel versions with the sprd I2C driver present or relevant. The bundle lists Linux as affected and provides stable kernel fix commits. Systems without this driver or already carrying the referenced fixes are less likely exposed.
Exploitation context
The CVSS vector is local, high-complexity, low-privilege, no user interaction, and availability-only. KEV is false, and the supplied sources do not report active exploitation or public weaponization. Evidence supports treating this as a reliability and local denial-of-service risk, not a remote compromise issue.
Researcher notes
The key evidence is the upstream fix rationale: pm_runtime_get_sync can increment the PM reference count even when it fails, so the usage counter can leak. The source bundle does not provide exploit details, affected distributions, or non-kernel mitigations. Validate exposure through kernel source/package provenance and driver presence.
Mitigation direction
- Apply Linux kernel updates containing the referenced stable fixes.
- Confirm downstream vendor kernels have backported the sprd I2C runtime PM fix.
- Prioritize systems where local untrusted users or workloads can reach affected kernels.
- If no update is available, monitor vendor guidance; no workaround is named in sources.
Validation and detection
- Inventory Linux kernel versions against the affected and fixed versions in vendor advisories.
- Check whether the deployed kernel includes one of the referenced stable commits.
- Determine whether the sprd I2C driver is built, loaded, or used on target systems.
- Review vendor kernel changelogs for the pm_runtime_resume_and_get backport.
Public sources used
- CVE Program
- CVE List V5
- Linux stable commit 7e1764312440c5df9dfe6b436035a03673b0c1b9
- Linux stable commit e547640cee7981fd751d2c9cde3a61bdb678b755
- Linux stable commit 9223505e938ba3db5907e058f4209770cff2f2a7
- Linux stable commit d3406ab52097328a3bc4cbe124bfd8f6d51fb86f
- Linux stable commit 3a4f326463117cee3adcb72999ca34a9aaafda93
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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CVE-2020-36780 mapping review
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Open ATT&CK lookup- Severity
- Medium
- CVSS
- 4.7 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/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.
SSVC decision data
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:H/PR:L/UI:N/S:U/C:N/I:N/A:H13.6CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
4.7MediumVector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://git.kernel.org/stable/c/7e1764312440c5df9dfe6b436035a03673b0c1b9CVE reference, Linux
- https://git.kernel.org/stable/c/e547640cee7981fd751d2c9cde3a61bdb678b755CVE reference, Linux
- https://git.kernel.org/stable/c/9223505e938ba3db5907e058f4209770cff2f2a7CVE reference, Linux
- https://git.kernel.org/stable/c/d3406ab52097328a3bc4cbe124bfd8f6d51fb86fCVE reference, Linux
- https://git.kernel.org/stable/c/3a4f326463117cee3adcb72999ca34a9aaafda93CVE reference, Linux
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.