CVE-2020-13933

Apache Shiro before 1.6.0, when using Apache Shiro, a specially crafted HTTP request may cause an authentication bypass.

Published: 2020-08-17 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-13933 is rated Moderate Risk (59.5/100): CVSS High severity, with high exploitation likelihood (EPSS 48.02%, 99th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. 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-2020-13933

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 80.93% 48.02% -32.91%
2 2026-05-03 69.49% 80.93% +11.44%
3 2025-11-21 — 69.49% —

Full EPSS history (17 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-13933

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N 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:N)
Service keeps running; no real outage angle.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N 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:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2020-13933

GitHub Security Advisory for CVE-2020-13933

GHSA-2vgm-wxr3-6w2j · Severity: high · Ecosystem: maven — Authentication bypass in Apache Shiro

OS Trackers for CVE-2020-13933

vendor priority summary link
debian not yet assigned CVE-2020-13933 not yet assigned priority: Debian including 1 source packages (shiro), 4 status rows across 4 suites (bookworm, bullseye, sid, trixie): resolved 4. https://security-tracker.debian.org/tracker/CVE-2020-13933
redhat high — https://access.redhat.com/security/cve/CVE-2020-13933
ubuntu medium CVE-2020-13933 medium priority: Ubuntu including 1 source packages (shiro), 11 status rows across 11 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, trusty, upstream, xenial): ignored 5, released 4, DNE 1, needs-triage 1. https://ubuntu.com/security/CVE-2020-13933

Affected software / configurations for CVE-2020-13933

Vendor Product Version Raw CPE
apache shiro < 1.6.0 cpe:2.3:a:apache:shiro:*:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

References for CVE-2020-13933

URL Tags
https://lists.apache.org/thread.html/r18b45d560d76c4260813c802771cc9678aa651fb8340e09366bfa198%40%3Cdev.geode.apache.org%3E
https://lists.apache.org/thread.html/r4506cedc401d6b8de83787f8436aac83956e411d66848c84785db46d%40%3Cdev.shiro.apache.org%3E
https://lists.apache.org/thread.html/r4c1e1249e9e1acb868db0c80728c13f448d07333da06a0f1603c0a33%40%3Cdev.shiro.apache.org%3E
https://lists.apache.org/thread.html/r539f87706094e79c5da0826030384373f0041068936912876856835f%40%3Cdev.shiro.apache.org%3E Mailing List Vendor Advisory
https://lists.apache.org/thread.html/r575301804bfac87a064359cf4b4ae9d514f2d10db7d44120765f4129%40%3Cdev.shiro.apache.org%3E
https://lists.apache.org/thread.html/r6ea0224c1971a91dc6ade1f22508119a9c3bd56cef656f0c44bbfabb%40%3Cdev.shiro.apache.org%3E
https://lists.apache.org/thread.html/r70098e336d02047ce4d4e69293fe8d558cd68cde06f6430398959bc4%40%3Cdev.shiro.apache.org%3E
https://lists.apache.org/thread.html/r70b907ccb306e9391145e2b10f56cc6914a245f91720a17a486c020a%40%3Cdev.shiro.apache.org%3E
https://lists.apache.org/thread.html/r8097b81905f2a113ebdf925bcbc6d8c9d6863c807c9ee42e1e7c9293%40%3Cdev.shiro.apache.org%3E
https://lists.apache.org/thread.html/r852971e28f54cafa7d325bd7033115c67d613b112a2a1076817390ac%40%3Cdev.shiro.apache.org%3E
https://lists.apache.org/thread.html/r9d93dfb5df016b1a71a808486bc8f9fbafebbdbc8533625f91253f1d%40%3Cdev.shiro.apache.org%3E
https://lists.apache.org/thread.html/r9ea6d8560d6354d41433ad006069904f0ed083527aa348b5999261a7%40%3Cdev.geode.apache.org%3E
https://lists.apache.org/thread.html/rb47d88af224e396ee34ffb88ee99fb6d04510de5722cf14b7137e6bc%40%3Cdev.shiro.apache.org%3E
https://lists.apache.org/thread.html/rb5edf49cd1451475dbcf53826ba6ef1bb7872dd6493d6112eb0c2bad%40%3Cdev.shiro.apache.org%3E
https://lists.apache.org/thread.html/re25b8317b00a50272a7252c4552cf1a81a97984cc2111ef7728e48e0%40%3Cdev.shiro.apache.org%3E
https://lists.debian.org/debian-lts-announce/2021/08/msg00002.html Mailing List Third Party Advisory
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