Security readout for executives and security teams
Plain-English summary
CVE-2021-26635 affects Bandisoft's ark library, used to process files. A crafted file can manipulate a size/offset check and trigger a stack buffer overflow. The stated impact includes possible remote code execution, but the CVSS vector requires local access and user interaction.
Executive priority
Treat as high priority where affected software processes external files, because successful exploitation could compromise confidentiality, integrity, and availability. Prioritize inventory and vendor confirmation first, since the provided data does not name affected versions or a specific fixed release.
Technical view
The vulnerability is a CWE-121 stack buffer overflow in ark library file-size verification. Incorrect data type use allows an attacker-controlled file offset to be misread, leading to stack memory corruption. CVSS 3.1 is 7.8 with local attack vector, low complexity, no privileges, and required user interaction.
Likely exposure
Exposure is likely where Bandisoft ark library is installed or embedded in applications that open attacker-supplied files. The provided sources do not identify specific versions, product integrations, file formats, or default deployment locations.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation evidence. Exploitation requires a malicious target file and user interaction under the published CVSS vector. Public sources provided describe potential code execution impact but do not provide exploit status.
Researcher notes
Key uncertainty is product scope. The CVE names Bandisoft ark library with unspecified versions only. The technical root cause is type misuse during file-size verification, enabling offset manipulation and stack overflow. Avoid assuming exploitation in the wild without KEV or corroborating source evidence.
Mitigation direction
- Check Bandisoft and KRCERT guidance for affected versions and fixes.
- Update or replace ark library where vendor remediation is available.
- Reduce handling of untrusted files in affected workflows.
- Process untrusted files in isolated, least-privilege environments.
- Monitor vendor advisories because affected versions are unspecified.
Validation and detection
- Inventory systems and applications using Bandisoft ark library.
- Confirm library versions against Bandisoft or KRCERT advisory details.
- Identify workflows that open files from external or untrusted sources.
- Review crash or EDR telemetry around archive/file parsing components.
- Document unresolved version uncertainty for vulnerability management tracking.
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-121: 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 lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-26635 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
- 7.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/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:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H1.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.krcert.or.kr/krcert/secNoticeView.do?bulletin_writing_sequence=66747CVE 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.
Stack-based Buffer Overflow
Stack-based Buffer Overflow represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.