How severe is CVE-2021-33642?

CVE-2021-33642 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-33642 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-33642?

CVE-2021-33642 affects Openeuler Byacc. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-33642?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-33642 published?

CVE-2021-33642 was published on 2023-01-20 and last updated on 2026-06-17.

CVE-2021-33642

CVE-2021-33642 is a medium-severity vulnerability in Openeuler Byacc with a CVSS 3.x base score of 5.5. 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-835.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
EPSS exploit prediction: 0% (13th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-835
Affected product: Openeuler Byacc
Published: 2023-01-20
Last modified: 2026-06-17

Description

When a file is processed, an infinite loop occurs in next_inline() of the more_curly() function.

Frequently asked questions

What is CVE-2021-33642?: When a file is processed, an infinite loop occurs in next_inline() of the more_curly() function.
How severe is CVE-2021-33642?: CVE-2021-33642 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-33642 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-33642?: CVE-2021-33642 affects Openeuler Byacc. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-33642?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-33642 published?: CVE-2021-33642 was published on 2023-01-20 and last updated on 2026-06-17.

References

https://gitee.com/src-openeuler/byacc/commit/50225f48c6b53e9d7c936681a06682404cb8ec4d

Affected products (1)

cpe:2.3:a:openeuler:byacc:*:*:*:*:*:*:*:*

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