CVE-2021-31920
CVE-2021-31920 is a medium-severity vulnerability in Istio with a CVSS 3.x base score of 6.5. 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-706.
Key facts
- Severity: Medium (CVSS 3.x base score 6.5)
- CVSS v2: 4.0
- EPSS exploit prediction: 1% (64th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-706
- Affected product: Istio
- Published:
- Last modified:
Description
Istio before 1.8.6 and 1.9.x before 1.9.5 has a remotely exploitable vulnerability where an HTTP request path with multiple slashes or escaped slash characters (%2F or %5C) could potentially bypass an Istio authorization policy when path based authorization rules are used.
Frequently asked questions
- What is CVE-2021-31920?
- Istio before 1.8.6 and 1.9.x before 1.9.5 has a remotely exploitable vulnerability where an HTTP request path with multiple slashes or escaped slash characters (%2F or %5C) could potentially bypass an Istio authorization policy when path based authorization rules are used.
- How severe is CVE-2021-31920?
- CVE-2021-31920 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
- Is CVE-2021-31920 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (64th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-31920?
- CVE-2021-31920 affects Istio. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2021-31920?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- When was CVE-2021-31920 published?
- CVE-2021-31920 was published on 2021-05-27 and last updated on 2026-06-17.
References
Affected products (1)
- cpe:2.3:a:istio:istio:*:*:*:*:*:*:*:*
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