Security readout for executives and security teams
Plain-English summary
CVE-2021-35942 is a glibc wordexp flaw that can make affected software crash or expose memory when untrusted crafted input reaches that function. The business risk depends on whether exposed applications use wordexp with user-controlled patterns. Treat it seriously because glibc is widely embedded, but exposure is application-dependent.
Executive priority
Prioritize remediation for exposed Linux services and managed appliances because the library is foundational and the CVSS score is critical. Do not assume every glibc system is remotely exploitable; validate whether vulnerable wordexp usage is reachable before emergency disruption.
Technical view
GNU C Library through 2.33 has a wordexp parse_param calculation issue caused by use of atoi where strtoul was needed. A crafted pattern supplied to wordexp can trigger denial of service or arbitrary memory read. The CVE is mapped to CWE-704 and scored CVSS 3.1 9.1.
Likely exposure
Exposure is most likely on Linux systems, appliances, containers, or applications using glibc through 2.33 where wordexp processes untrusted input. Systems with patched distribution glibc packages or applications that never pass untrusted patterns to wordexp have lower practical exposure.
Exploitation context
The provided sources do not show CISA KEV listing or confirmed active exploitation. The described attack path requires a vulnerable glibc and a reachable application path that calls wordexp on attacker-controlled patterns. Public impact is denial of service or information disclosure, not integrity compromise.
Researcher notes
The key technical evidence is Sourceware bug 28011 and glibc commit 5adda61f62b77384718b4c0d8336ade8f2b4b35c. Public CVE metadata lists generic affected product data, so asset correlation should rely on vendor and distribution package advisories rather than CPE matching alone.
Mitigation direction
- Apply vendor or distribution glibc security updates for affected systems.
- Prioritize internet-facing services that may process shell-like patterns or paths.
- Check appliance vendor advisories, including NetApp where relevant.
- Rebuild or redeploy containers based on affected glibc images.
- Review application use of wordexp with untrusted input.
Validation and detection
- Inventory glibc versions and flag systems at or below 2.33.
- Check distro advisory status, including Gentoo GLSA-202208-24 and Debian DLA-3152-1.
- Identify code paths that call wordexp with user-controlled patterns.
- Confirm patched package versions are deployed across hosts and containers.
- Document compensating controls where patching is delayed.
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-704: 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-2021-35942 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
- 9.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/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:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H3.95.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.1CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://sourceware.org/glibc/wiki/Security%20ExceptionsCVE reference
- https://sourceware.org/bugzilla/show_bug.cgi?id=28011CVE reference
- https://sourceware.org/git/?p=glibc.git%3Ba=commit%3Bh=5adda61f62b77384718b4c0d8336ade8f2b4b35cCVE reference
- https://security.netapp.com/advisory/ntap-20210827-0005/CVE reference
- GLSA-202208-24CVE reference · vendor-advisory
- [debian-lts-announce] 20221017 [SECURITY] [DLA 3152-1] glibc security updateCVE reference · mailing-list
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.
Incorrect Type Conversion or Cast
Incorrect Type Conversion or Cast represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.