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CVE Record

CVE-2021-28835: Buffer Overflow vulnerability in XNView before 2.50, allows local attackers to execute arbitrary code via c...

Buffer Overflow vulnerability in XNView before 2.50, allows local attackers to execute arbitrary code via crafted GEM bitmap file.

HighCVSS 7.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2021-28835 is a high-severity buffer overflow in XNView before 2.50. A user would likely need to open a malicious GEM bitmap file. If triggered, the issue could allow code execution with serious confidentiality, integrity, and availability impact.

Executive priority

Treat as a prioritized workstation patching issue, especially for teams handling external image files. It is not KEV-listed in the supplied data, but successful exploitation could execute code after user interaction.

Technical view

The CVE describes a local, user-interaction-required buffer overflow in XNView before 2.50 when processing a crafted GEM bitmap file. CVSS 3.1 is 7.8 with AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Likely exposure

Exposure is most likely on workstations where XNView before 2.50 is installed and users open untrusted or externally supplied image files. The source bundle’s structured affected fields are incomplete, but the title and description identify XNView before 2.50.

Exploitation context

The bundle does not cite CISA KEV listing or any source confirming active exploitation. Practical abuse would likely involve getting a user to open a crafted GEM bitmap file in an affected local XNView installation.

Researcher notes

Evidence is sparse: no CWE is listed and affected CPE data is absent. Analysis relies on the CVE description, CVSS vector, and referenced XNView changelog/forum links. Do not assume affected products beyond XNView before 2.50.

Mitigation direction

  • Upgrade XNView installations older than 2.50 to 2.50 or a vendor-current release.
  • Check the XNView changelog and vendor forum for version-specific remediation guidance.
  • Restrict opening untrusted GEM bitmap files until affected installations are updated.
  • Reduce file association exposure for uncommon image formats where operationally feasible.

Validation and detection

  • Inventory endpoints for XNView installations and record exact versions.
  • Flag any XNView version older than 2.50 for remediation.
  • Confirm whether users process GEM bitmap files from external or untrusted sources.
  • Review endpoint controls for alerts involving suspicious image-file handling by XNView.
Prepared
Confidence
medium
Sources
4

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

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

description · low confidence lookup

Execution behavior lookup

The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2021-28835 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
High
CVSS
7.8 (3.1)
Known Exploited
No
Published

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

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
3Source 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
7.8CVSS 3.1HighCVSS:3.1/AC:L/AV:L/A:H/C:H/I:H/PR:N/S:U/UI:R1.85.9Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

7.8High
CVSS 3.1 vector shape for CVE-2021-28835Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

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.