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CVE-2020-17523 Apache Shiro

Affected softwareApache Shiro
Severity9.8 Critical CVSS 3.1 2 scores
Fixed in1.7.1
WeaknessImproper authentication (CWE-287)
Published3 Feb 2021
Updated17 Jun 2026

Description

Apache Shiro before 1.7.1, when using Apache Shiro with Spring, a specially crafted HTTP request may cause an authentication bypass.

Exploitation status

Exploited

Real-world exploitation reported by VulnCheck KEV. CISA has not confirmed it.

  • CISA KEV not listed
  • VulnCheck KEV listed Exploitation reported in the wild. Honeypot sightings · 1 exploit · earliest 2026-11-10.
  • CISA Vulnrichment no assessment published
  • Indexed PoC 1 indexed Published artifacts you can open, in GitHub PoC; first seen 2021-02-03.
  • EPSS 86% chance in 30 days A model's forecast, not a report of exploitation. Higher than 99.7% of all scored CVEs.

VulnCheck KEV

Exploitation evidence from VulnCheck Known Exploited Vulnerabilities (VulnCheck KEV), used under VulnCheck's community terms. View CVE-2020-17523 in VulnCheck (free account).

EvidenceSourceDetailDate
Honeypot sighting VulnCheck canaries Exploitation attempts seen on 4 days 2026-11-10 to 2026-11-13
Exploit reference VulnCheck XDB 9b43dc813ff5 Exploit type: initial-access 2021-02-03
IndexArtifactStarsFirst seen
GitHub PoC shiro-cve-2020-17523 漏洞的两种绕过姿势分析 以及配套的漏洞环境 118 2021-02-03

Waratek protection

Mitigation candidate

A kind of vulnerability Waratek's rules address, with exploit code published or exploitation reported. No rule exists and none is planned yet. The decision below says what we found to build a rule from.

  • Protection none
  • Action unverified
  • Review automated Inferred
  • Record active
Decided by The affected package being open source on Maven, so the fix can be read
Finding This CVE affects an open-source Java library published on Maven Central (Maven packages: org.apache.shiro:shiro-web, org.apache.shiro:shiro-spring, org.apache.shiro:shiro-spring-boot-starter), so it is squarely in ARMR's territory and the source needed to understand the defect is public. That makes it a candidate for an ARMR patch rule. No rule exists and none is scheduled: the diff between the affected and fixed versions has not been read, and a closer look may find no hook point ARMR can act on.

CVSS

9.8 CRITICAL v3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H 2 metrics

We show the highest score from the newest CVSS version. Scores from different versions can't be compared, and the first score listed is sometimes a 0.0 placeholder.

VersionScoreBandVectorAssignerType
CVSS 3.1 9.8 CRITICAL CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H NVD Primary published
CVSS 2.0 9.0 none AV:N/AC:L/Au:N/C:P/I:P/A:C NVD Primary

Affected software and releases

Maven packages

Affected and fixed versions, from OSV.dev
PackageIntroducedFixedLast affected
org.apache.shiro:shiro-web 0 1.7.1 unbounded
org.apache.shiro:shiro-spring 0 1.7.1 unbounded
org.apache.shiro:shiro-spring-boot-starter 0 1.7.1 unbounded

Products and versions

4 products, 4 version entries
SourceVendorProductSchemeAffected versions
nvd apache shiro generic < 1.7.1
osv org.apache.shiro shiro-spring generic < 1.7.1
osv org.apache.shiro shiro-spring-boot-starter generic < 1.7.1
osv org.apache.shiro shiro-web generic < 1.7.1

References

URLTags
https://github.com/apache/shiro/pull/263 WEB
https://issues.apache.org/jira/browse/SHIRO-797 WEB
https://lists.apache.org/thread.html/r5b93ddf97e2c4cda779d22fab30539bdec454cfa5baec4ad0ffae235@%3Cgitbox.activemq.apache.org%3E WEB
https://lists.apache.org/thread.html/r679ca97813384bdb1a4c087810ba44d9ad9c7c11583979bb7481d196@%3Cdev.shiro.apache.org%3E WEB
https://lists.apache.org/thread.html/r8244fd0831db894d5e89911ded9c72196d395a90ae655414d23ed0dd@%3Cusers.activemq.apache.org%3E WEB
https://lists.apache.org/thread.html/r852971e28f54cafa7d325bd7033115c67d613b112a2a1076817390ac@%3Cdev.shiro.apache.org%3E WEB
https://lists.apache.org/thread.html/r9d93dfb5df016b1a71a808486bc8f9fbafebbdbc8533625f91253f1d@%3Cdev.shiro.apache.org%3E WEB
https://lists.apache.org/thread.html/rce5943430a6136d37a1f2fc201d245fe094e2727a0bc27e3b2d43a39%40%3Cdev.shiro.apache.org%3E WEB
https://lists.apache.org/thread.html/rd4b613e121438b97e3eb263cac3137caddb1dbd8f648b73a4f1898a6@%3Cissues.activemq.apache.org%3E WEB
https://lists.apache.org/thread.html/re25b8317b00a50272a7252c4552cf1a81a97984cc2111ef7728e48e0@%3Cdev.shiro.apache.org%3E WEB

Timeline

Published2021-02-03By the CVE Program.
NVD record modified2026-06-17NVD's own last-modified date for this record.
VulnCheck KEV: earliest evidence2026-11-10Date of the oldest evidence of exploitation in VulnCheck KEV's record. VulnCheck does not publish the date it listed the CVE.
VulnCheck KEV: latest evidence2026-11-13Date of the newest report, exploit reference or honeypot sighting in VulnCheck KEV's record.