CVE-2021-35942

The wordexp function in the GNU C Library (aka glibc) through 2.33 may crash or read arbitrary memory in parse_param (in posix/wordexp.c) when called with an untrusted, crafted pattern, potentially resulting in a denial of service or disclosure of information. This occurs because atoi was used but strtoul should have been used to ensure correct calculations.

Published: 2021-07-22 Last update: 2026-02-13 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-35942 is rated High Risk (67/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 2.68%). Core evidence: EPSS rose +1.27% over the last day, indicating growing attacker interest. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-35942

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 1.41% 2.68% +1.27%
2 2026-05-18 1.60% 1.41% -0.19%
3 2026-04-12 1.60%

Full EPSS history (28 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-35942

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.1 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 5.2 [email protected]
9.1 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 5.2 134c704f-9b21-4f2e-91b3-4a467353bcc0
6.4 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
10.0 4.9 [email protected]

Weakness enumeration for CVE-2021-35942

OS Trackers for CVE-2021-35942

vendor priority summary link
debian not yet assigned CVE-2021-35942 not yet assigned priority: Debian including 1 source packages (glibc), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-35942
gentoo normal CVE-2021-35942: 1 GLSA(s) (202208-24), 1 atom(s) (sys-libs/glibc); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-35942
redhat medium https://access.redhat.com/security/cve/CVE-2021-35942
suse medium CVE-2021-35942 severity moderate: SUSE including 860 source package names (0.1.0:glibc-2.26-13.59.1, 0.1.75:glibc-2.26-13.59.1, …), 2312 product×package rows across 425 product lines (Container bci/bci-base-fips, Container bci/bci-busybox, … (425 product lines)): Fixed 2158, Known Affected 154. https://www.suse.com/security/cve/CVE-2021-35942/
ubuntu low CVE-2021-35942 low priority: Ubuntu including 2 source packages (eglibc, glibc), 32 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 15, not-affected 9, released 4, ignored 2, needed 1, needs-triage 1. https://ubuntu.com/security/CVE-2021-35942

Affected software / configurations for CVE-2021-35942

Vendor Product Version Raw CPE
gnu glibc < 2.31 cpe:2.3:a:gnu:glibc:*:*:*:*:*:*:*:*
netapp active_iq_unified_manager cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:vmware_vsphere:*:*
netapp e-series_santricity_os_controller >= 11.0, <= 11.70.1 cpe:2.3:a:netapp:e-series_santricity_os_controller:*:*:*:*:*:*:*:*
netapp hci_management_node cpe:2.3:a:netapp:hci_management_node:-:*:*:*:*:*:*:*
netapp ontap_select_deploy_administration_utility cpe:2.3:a:netapp:ontap_select_deploy_administration_utility:-:*:*:*:*:*:*:*
netapp solidfire cpe:2.3:a:netapp:solidfire:-:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

References for CVE-2021-35942

cvelogic Threat Intelligence