How severe is CVE-2021-29998?

CVE-2021-29998 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-29998 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-29998?

CVE-2021-29998 primarily affects Windriver Vxworks. In total, 36 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-29998?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-29998 published?

CVE-2021-29998 was published on 2021-04-13 and last updated on 2026-06-17.

CVE-2021-29998

CVE-2021-29998 is a critical-severity vulnerability in Windriver Vxworks with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (82nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Windriver Vxworks
Published: 2021-04-13
Last modified: 2026-06-17

Description

An issue was discovered in Wind River VxWorks before 6.5. There is a possible heap overflow in dhcp client.

Frequently asked questions

What is CVE-2021-29998?: An issue was discovered in Wind River VxWorks before 6.5. There is a possible heap overflow in dhcp client.
How severe is CVE-2021-29998?: CVE-2021-29998 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-29998 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-29998?: CVE-2021-29998 primarily affects Windriver Vxworks. In total, 36 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-29998?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-29998 published?: CVE-2021-29998 was published on 2021-04-13 and last updated on 2026-06-17.

References

Affected products (36)

cpe:2.3:o:windriver:vxworks:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:ruggedcom_win_subscriber_station_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_x200-4_p_irt_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_x201-3p_irt_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_x201-3p_irt_pro_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_x202-2_irt_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_x202-2p_irt_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_x202-2p_irt_pro_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_x204_irt_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_x204_irt_pro_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_x204-2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_x204-2fm_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_x204-2ld_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_x204-2ld_ts_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_x204-2ts_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_x206-1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_x206-1ld_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_x208_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_x208_pro_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_x212-2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_x212-2ld_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_x216_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_x224_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_x300_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_x408_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_xf201-3p_irt_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_xf202-2p_irt_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_xf204_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_xf204_irt_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_xf204-2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_xf204-2ba_irt_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_xf206-1_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:scalance_xf208_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_rf_181_eip_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:simatic_rf_182c_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:siemens:sinamics_perfect_harmony_gh180_firmware:*:*:*:*:*:*:*:*

More vulnerabilities in Windriver Vxworks

CVE-2013-0714 — Critical (CVSS 10.0): IPSSH (aka the SSH server) in Wind River VxWorks 6.5 through 6.9 allows remote attackers to execute arbitrary code or…
CVE-2020-35198 — Critical (CVSS 9.8): An issue was discovered in Wind River VxWorks 7. The memory allocator has a possible integer overflow in calculating a…
CVE-2021-29999 — Critical (CVSS 9.8): An issue was discovered in Wind River VxWorks through 6.8. There is a possible stack overflow in dhcp server.
CVE-2016-20009 — Critical (CVSS 9.8): A DNS client stack-based buffer overflow in ipdnsc_decode_name() affects Wind River VxWorks 6.5 through 7. NOTE: This…
CVE-2019-12262 — Critical (CVSS 9.8): Wind River VxWorks 6.6, 6.7, 6.8, 6.9 and 7 has Incorrect Access Control in the RARP client component. IPNET security…
CVE-2019-12261 — Critical (CVSS 9.8): Wind River VxWorks 6.7 though 6.9 and vx7 has a Buffer Overflow in the TCP component (issue 3 of 4). This is an IPNET…

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