Security readout for executives and security teams
Plain-English summary
A memory-read bug exists in Zint Barcode Generator versions before 2.10.0. It can read one byte beyond the intended buffer during barcode processing. Public data does not provide CVSS, detailed impact, or active exploitation evidence. Treat it as a dependency hygiene issue: update affected Zint installations and verify whether Zint handles untrusted input.
Executive priority
Handle through normal vulnerability management unless Zint is exposed to untrusted input in production workflows. There is no cited evidence of active exploitation, but the affected version boundary is clear enough to justify upgrade verification.
Technical view
CVE-2021-39247 is a one-byte buffer over-read in Zint Barcode Generator before 2.10.0, tied to is_last_single_ascii in code1.c and rs_encode_uint in reedsol.c. The provided sources list a SourceForge ticket and code commit, but no CWE, CVSS vector, exploitability analysis, or affected CPEs.
Likely exposure
Exposure is limited to systems running or embedding Zint Barcode Generator before 2.10.0. Priority rises where Zint processes externally supplied barcode content or runs in automated services. The source bundle does not identify packaged downstream products or platforms.
Exploitation context
The source bundle does not show active exploitation, public exploit use, or KEV listing. Evidence supports a memory safety defect and an upstream fix reference, but not practical attack conditions or reliable business impact.
Researcher notes
The record lacks CVSS, CWE, CPEs, and detailed exploitability context. Analysis should stay close to the upstream ticket, commit, and version boundary. Avoid overstating impact beyond a one-byte over-read before 2.10.0.
Mitigation direction
- Upgrade Zint Barcode Generator to 2.10.0 or later where present.
- Check vendor or distribution packages for backported fixes.
- Reduce exposure by avoiding untrusted barcode inputs until updated.
- Monitor upstream Zint and distribution advisories for added impact details.
Validation and detection
- Inventory systems and applications for Zint Barcode Generator usage.
- Confirm installed Zint versions are 2.10.0 or later.
- Review dependency manifests and container images for bundled Zint copies.
- Check whether Zint processes externally supplied barcode data.
- Record compensating controls if immediate upgrade is not possible.
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.
CVE-2021-39247 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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 and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://sourceforge.net/p/zint/tickets/232/CVE reference · x_refsource_MISC
- https://sourceforge.net/p/zint/code/ci/9b02cd52214e80f945bff41fc94bc1e17e15810c/CVE 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.