Security readout for executives and security teams
Plain-English summary
CVE-2021-21947 affects Accusoft ImageGear 19.10, an image-processing component. A malicious JPEG-JFIF file could trigger memory corruption in the lossless Huffman parser. For organizations that process user-supplied images with this version, the business concern is potential compromise of the image-processing service.
Executive priority
Prioritize this for any business service that processes external images with ImageGear 19.10. If ImageGear is absent, urgency drops sharply. If present on internet-facing upload or conversion paths, treat remediation as high priority due to critical CVSS impact.
Technical view
The flaw is two heap-based buffer overflows in ImageGear 19.10's JPEG-JFIF lossless Huffman parsing. The source states the overflow occurs when SOF3 precision is greater than or equal to 9. CVSS 3.0 is 9.8 with network attack vector, no privileges, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is most likely where Accusoft ImageGear 19.10 processes untrusted or externally supplied JPEG/JFIF files, such as upload, conversion, preview, or document-processing workflows. The provided sources identify only ImageGear 19.10 as affected.
Exploitation context
The bundle does not show CISA KEV listing or active exploitation evidence. The public description says an attacker can provide a specially crafted file to trigger the vulnerability. Treat exploit status as unconfirmed unless vendor, KEV, or incident sources show otherwise.
Researcher notes
Evidence is limited to the CVE data and Talos reference in the bundle. The key technical marker is lossless JPEG-JFIF Huffman parsing with SOF3 precision at least 9. Avoid assuming affected downstream products unless their use of ImageGear 19.10 is confirmed.
Mitigation direction
- Check Accusoft guidance for fixed versions or vendor-recommended mitigations.
- Upgrade or replace ImageGear 19.10 where vendor guidance confirms remediation.
- Limit untrusted JPEG/JFIF processing by systems using ImageGear 19.10.
- Isolate image-processing services from sensitive systems where feasible.
- Apply file-type and content validation before ImageGear processing.
Validation and detection
- Inventory applications and services that include Accusoft ImageGear.
- Confirm whether any deployed ImageGear version is 19.10.
- Map workflows that process uploaded, emailed, or external JPEG/JFIF files.
- Check vendor advisory status before asserting a patched version.
- Review logs for crashes in ImageGear image-processing paths.
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
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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CWE-122: Exact CWE lookup
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Open ATT&CK lookupCVE-2021-21947 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
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-2021-1375CVE 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.
Heap-based Buffer Overflow
Heap-based Buffer Overflow represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.