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CVE Record

CVE-2020-22916: An issue discovered in XZ 5.2.5 allows attackers to cause a denial of service via decompression of a crafte...

An issue discovered in XZ 5.2.5 allows attackers to cause a denial of service via decompression of a crafted file. NOTE: the vendor disputes the claims of "endless output" and "denial of service" because decompression of the 17,486 bytes always results in 114,881,179 bytes, which is often a reasonable size increase.

MediumCVSS 5.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This CVE describes a disputed denial-of-service claim against XZ 5.2.5 when decompressing a crafted file. The reported effect is availability impact from expansion during decompression, not data theft or code execution. Business urgency is limited unless untrusted XZ files are automatically processed in critical workflows.

Executive priority

Treat this as a low-urgency availability review unless your environment automatically decompresses untrusted XZ files. Prioritize validation in upload, mail, build, and scanning pipelines. The vendor dispute and absence of KEV evidence argue against emergency response.

Technical view

The record scores CVSS 5.5 with local attack vector, low complexity, no privileges, required user interaction, and high availability impact. The vendor disputes the claim, stating the cited 17,486-byte input deterministically expands to 114,881,179 bytes and is often a reasonable size increase.

Likely exposure

Most likely exposure is endpoints, build systems, upload handlers, or content-processing jobs that decompress attacker-supplied XZ files. The source bundle does not identify a remote network service, specific downstream products, or confirmed affected CPEs beyond the XZ 5.2.5 claim.

Exploitation context

No active exploitation is supported by the provided sources, and the CVE is not listed as KEV. Exploitation requires a crafted file to be decompressed locally or by a workflow acting on user-supplied content. The vendor dispute materially lowers confidence in practical denial-of-service impact.

Researcher notes

Evidence is incomplete and contested. The CVE description names XZ 5.2.5 but affected vendor/product metadata is n/a. The key technical dispute is whether deterministic expansion to about 115 MB constitutes a denial of service. Avoid overstating exploitability without downstream vendor confirmation.

Mitigation direction

  • Check XZ and operating-system vendor guidance for package status.
  • Limit automatic decompression of untrusted XZ files in critical workflows.
  • Apply resource limits to services that process uploaded compressed files.
  • Review Debian, Red Hat, and SUSE trackers for distribution-specific handling.
  • Do not assume a patch exists unless vendor guidance names one.

Validation and detection

  • Inventory systems and workflows using XZ or liblzma 5.2.5.
  • Identify services that decompress user-supplied XZ archives.
  • Check whether decompression jobs have memory, disk, and runtime limits.
  • Review vendor trackers for affected or disputed status.
  • Confirm no critical automation blindly processes untrusted compressed files.
Prepared
Confidence
medium
Sources
8

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-2020-22916 mapping review

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.5 (3.1)
Known Exploited
No
Published

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

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.

1CVSS vectors
0Timeline events
0ADP providers
7Source links

CVSS vector scores

1 official score

We 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.

ScoreVersionSeverityVectorExploitImpactSource
5.5CVSS 3.1MediumCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H1.83.6Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

5.5Medium
CVSS 3.1 vector shape for CVE-2020-22916Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.