Security readout for executives and security teams
Plain-English summary
CVE-2021-43453 is a reported memory-safety flaw in JerryScript 2.4.0 and earlier. A specially handled JavaScript parsing path can read outside expected memory bounds. Public data in the bundle does not provide a CVSS score, confirmed patch, affected CPEs, or exploitation evidence.
Executive priority
Handle as an inventory and exposure-confirmation item, not a confirmed emergency. Escalate priority if JerryScript is embedded in products that parse untrusted scripts, especially in externally reachable or safety-sensitive environments.
Technical view
The issue is described as a heap-based buffer overflow involving an out-of-bounds read in parser_parse_for_statement_start in js-parser-statm.c. It affects JerryScript 2.4.0 and prior versions and is noted as similar to CVE-2020-29657. The bundle provides no detailed exploitability analysis or fixed version.
Likely exposure
Exposure is most likely where JerryScript 2.4.0 or earlier is embedded in products, firmware, test harnesses, or services that parse JavaScript. The source bundle does not identify specific downstream products or deployment environments.
Exploitation context
The bundle does not show CISA KEV listing, active exploitation, public weaponization, or a proof-of-concept. Treat exploit status as unconfirmed. Risk depends heavily on whether affected JerryScript parsing is reachable by untrusted JavaScript input.
Researcher notes
Evidence is sparse: no CVSS, CWE list, CPEs, fixed release, or exploitation confirmation are present in the bundle. Do not assume downstream product impact. The CVE references one GitHub issue and notes similarity to CVE-2020-29657, but separate validation is required.
Mitigation direction
- Inventory software and firmware for JerryScript 2.4.0 or earlier.
- Check JerryScript and vendor guidance for confirmed fixed versions.
- Restrict untrusted JavaScript parsing where affected versions are present.
- Prioritize remediation for internet-facing or user-supplied script parsing paths.
- Track the CVE record and linked GitHub issue for updates.
Validation and detection
- Review SBOMs, lockfiles, and source trees for JerryScript usage.
- Confirm embedded JerryScript versions in built artifacts or firmware images.
- Map whether untrusted users can reach JavaScript parsing paths.
- Document any compensating controls limiting script input or parser access.
- Recheck vendor advisories before closing remediation tickets.
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-2021-43453 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://github.com/jerryscript-project/jerryscript/issues/4754CVE 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.