Security readout for executives and security teams
Plain-English summary
Accusoft ImageGear 19.9 has a PNG parsing flaw that can corrupt memory when it receives a specially crafted malformed file. If business systems use ImageGear to process untrusted images, this could affect confidentiality, integrity, and availability. The supplied sources do not show active exploitation.
Executive priority
Treat this as a high-priority exposure review if ImageGear 19.9 processes customer, partner, or internet-supplied PNGs. Prioritize inventory and vendor remediation confirmation before broader compensating controls.
Technical view
CVE-2021-21808 is a CWE-120 heap buffer overflow in ImageGear 19.9 PNG png_palette_process. The CVSS 3.0 score is 8.1, with network attack vector, no privileges, no user interaction, high complexity, and high CIA impact. Evidence is limited to the CVE data and Talos reference.
Likely exposure
Exposure is most likely in applications or services that embed Accusoft ImageGear 19.9 and process PNG files, especially upload, conversion, preview, or document-processing workflows that accept external content.
Exploitation context
The source bundle says a specially crafted malformed file can trigger the vulnerability. It does not provide evidence of active exploitation, and CISA KEV status is false. The CVSS vector indicates high attack complexity despite severe potential impact.
Researcher notes
The public bundle identifies the vulnerable function and class of memory corruption but does not include patch details, affected build ranges beyond 19.9, or exploitation telemetry. Avoid assuming broader Accusoft products are affected without vendor evidence.
Mitigation direction
- Identify systems and products using Accusoft ImageGear 19.9.
- Check Accusoft or Talos guidance for a corrected release; sources do not name one.
- Isolate services that parse untrusted PNG files with ImageGear.
- Restrict untrusted image ingestion where business processes allow.
- Apply compensating monitoring around image-processing crashes or abnormal behavior.
Validation and detection
- Confirm whether ImageGear 19.9 is present in application inventories or SBOMs.
- Map where PNG files reach ImageGear parsing code paths.
- Determine whether external or unauthenticated users can supply images.
- Check vendor advisory or support channels for remediation status.
- Review crash telemetry for image-processing failures involving PNG files.
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
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-120: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-21808 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
- High
- CVSS
- 8.1 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:H/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:H/PR:N/UI:N/S:U/C:H/I:H/A:H2.25.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
8.1HighVector: CVSS:3.0/AV:N/AC:H/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-2021-1276CVE 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.
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.