Security readout for executives and security teams
Plain-English summary
Accusoft ImageGear 19.9 has a critical file-parsing flaw in TIF handling. A maliciously formed image file can trigger memory corruption through an out-of-bounds write. Systems that automatically process uploaded or emailed TIF files are the main concern.
Executive priority
Prioritize quickly if ImageGear 19.9 handles external files. The impact rating is critical, and file-processing bugs can affect public-facing workflows, but the bundle does not prove active exploitation.
Technical view
CVE-2021-21833 is improper array index validation in ImageGear 19.9 TIF IP_planar_raster_unpack functionality. The provided CVSS 3.0 score is 9.8, with network attack vector, low complexity, no privileges, no user interaction, unchanged scope, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is likely where Accusoft ImageGear 19.9 processes attacker-supplied malformed TIF files, including upload workflows, conversion services, document ingestion, or backend image-processing pipelines.
Exploitation context
The bundle states an attacker can provide a malicious file to trigger the bug. It does not cite CISA KEV listing or any source confirming active exploitation in the wild.
Researcher notes
Evidence is limited to CVE metadata and Talos reference details in the bundle. Do not assume affected versions beyond ImageGear 19.9 or confirmed fixes unless vendor guidance is reviewed.
Mitigation direction
- Identify all systems using Accusoft ImageGear 19.9.
- Check Accusoft and Talos guidance for fixed versions or vendor mitigations.
- Restrict untrusted TIF processing until remediation is confirmed.
- Apply strict file validation and isolate image-processing workloads.
- Monitor ingestion services for crashes or abnormal parser behavior.
Validation and detection
- Inventory application dependencies for Accusoft ImageGear 19.9.
- Review upload, email, and document-processing paths accepting TIF files.
- Confirm whether untrusted users can reach ImageGear parsing.
- Verify installed versions against vendor remediation guidance.
- Check logs for crashes linked to TIF processing.
Public sources used
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
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ATT&CK lookup starting points
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CWE-119: Exact CWE lookup
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Open ATT&CK lookupCVE-2021-21833 mapping review
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Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.8 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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.
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:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
9.8CriticalVector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://talosintelligence.com/vulnerability_reports/TALOS-2021-1296CVE reference · x_refsource_MISC
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.
Improper Restriction of Operations within the Bounds of a Memory Buffer
Improper Restriction of Operations within the Bounds of a Memory Buffer represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.