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NVD / CVE Program· CNA Linux

CVE-2023-52633: um: time-travel: fix time corruption

Noroxi assessment

Priority: Monitor (action score 20/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.22% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. A user must open a link or visit a page. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 0c7478a2da3f5fe106b4658338873d50c86ac7ab, 4f7dad73df4cdb2b7042103d3922745d040ad025, abe4eaa8618bb36c2b33e9cdde0499296a23448c.
  • Mentioned 2 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 0c7478a2da3f5fe106b4658338873d50c86ac7ab, 4f7dad73df4cdb2b7042103d3922745d040ad025, abe4eaa8618bb36c2b33e9cdde0499296a23448c or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: um: time-travel: fix time corruption In 'basic' time-travel mode (without =inf-cpu or =ext), we still get timer interrupts. These can happen at arbitrary points in time, i.e. while in timer_read(), which pushes time forward just a little bit. Then, if we happen to get the interrupt after calculating the new time to push to, but before actually finishing that, the interrupt will set the time to a value that's incompatible with the forward, and we'll crash because time goes backwards when we do the forwarding. Fix this by reading the time_travel_time, calculating the adjustment, and doing the adjustment all with interrupts disabled.

MediumCVSS 5.0 · v3.1—No exploit Fix available
Published
Apr 2, 2024
Updated
Jun 17, 2026
EPSS
0.2% · 13th percentile

Report tools

JSON

Action score

20

Monitor

Low priority for now.

CVSS
20 / 40 · 5.0 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2023-52633

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernelbefore 5.15.149
  • linux linux kernel5.16 and later · before 6.1.77
  • linux linux kernel6.2 and later · before 6.6.16
  • linux linux kernel6.7 and later · before 6.7.4

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 5.3affected
    • 065038706f77a56754e8f0c2556dab7e22dfe577 and later · before 0c7478a2da3f5fe106b4658338873d50c86ac7abaffected · git
    • 065038706f77a56754e8f0c2556dab7e22dfe577 and later · before 4f7dad73df4cdb2b7042103d3922745d040ad025affected · git
    • 065038706f77a56754e8f0c2556dab7e22dfe577 and later · before de3e9d8e8d1ae0a4d301109d1ec140796901306caffected · git
    • 065038706f77a56754e8f0c2556dab7e22dfe577 and later · before b427f55e9d4185f6f17cc1e3296eb8d0c4425283affected · git
    • 065038706f77a56754e8f0c2556dab7e22dfe577 and later · before abe4eaa8618bb36c2b33e9cdde0499296a23448caffected · git
    • before 5.3not affected · semver
    • 5.15.149 and later · up to and including 5.15.*not affected · semver
    • 6.1.77 and later · up to and including 6.1.*not affected · semver
    • 6.6.16 and later · up to and including 6.6.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.82-16.1.82-1
Debian:13linuxbefore 6.7.7-16.7.7-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2023-52631Apr 2, 2024 · fs/ntfs3: Fix an NULL dereference bug
    22Monitor
  • ← EarlierCVE-2023-52632Apr 2, 2024 · drm/amdkfd: Fix lock dependency warning with srcu
    22Monitor
  • Later →CVE-2023-52634Apr 2, 2024 · drm/amd/display: Fix disable_otg_wa logic
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux0c7478a2da3f5fe106b4658338873d50c86ac7abVendor (CNA)
Linux Linux4f7dad73df4cdb2b7042103d3922745d040ad025Vendor (CNA)
Linux Linuxabe4eaa8618bb36c2b33e9cdde0499296a23448cVendor (CNA)
Linux Linuxb427f55e9d4185f6f17cc1e3296eb8d0c4425283Vendor (CNA)
Linux Linuxde3e9d8e8d1ae0a4d301109d1ec140796901306cVendor (CNA)
debian:linux6.1.82-1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
Required
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-787 · Out-of-bounds Write

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records