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Vulnerability details: VCID-4te8-48t3-puca
Vulnerability ID VCID-4te8-48t3-puca
Aliases CVE-2021-21439
Summary DoS attack can be performed when an email contains specially designed URL in the body. It can lead to the high CPU usage and cause low quality of service, or in extreme case bring the system to a halt. This issue affects: OTRS AG ((OTRS)) Community Edition 6.0.x version 6.0.1 and later versions. OTRS AG OTRS 7.0.x version 7.0.26 and prior versions; 8.0.x version 8.0.13 and prior versions.
Status Published
Exploitability 0.5
Weighted Severity 5.9
Risk 3.0
Affected and Fixed Packages Package Details
Weaknesses (1)
CWE-755 Improper Handling of Exceptional Conditions
System Score Found at
epss 0.00509 https://api.first.org/data/v1/epss?cve=CVE-2021-21439
epss 0.00509 https://api.first.org/data/v1/epss?cve=CVE-2021-21439
epss 0.00509 https://api.first.org/data/v1/epss?cve=CVE-2021-21439
epss 0.00509 https://api.first.org/data/v1/epss?cve=CVE-2021-21439
epss 0.00509 https://api.first.org/data/v1/epss?cve=CVE-2021-21439
epss 0.00509 https://api.first.org/data/v1/epss?cve=CVE-2021-21439
epss 0.00509 https://api.first.org/data/v1/epss?cve=CVE-2021-21439
epss 0.00509 https://api.first.org/data/v1/epss?cve=CVE-2021-21439
epss 0.00509 https://api.first.org/data/v1/epss?cve=CVE-2021-21439
epss 0.00509 https://api.first.org/data/v1/epss?cve=CVE-2021-21439
epss 0.00509 https://api.first.org/data/v1/epss?cve=CVE-2021-21439
epss 0.00509 https://api.first.org/data/v1/epss?cve=CVE-2021-21439
epss 0.00509 https://api.first.org/data/v1/epss?cve=CVE-2021-21439
epss 0.00509 https://api.first.org/data/v1/epss?cve=CVE-2021-21439
epss 0.00509 https://api.first.org/data/v1/epss?cve=CVE-2021-21439
epss 0.00509 https://api.first.org/data/v1/epss?cve=CVE-2021-21439
epss 0.00509 https://api.first.org/data/v1/epss?cve=CVE-2021-21439
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2021-21439
cvssv2 4.3 https://nvd.nist.gov/vuln/detail/CVE-2021-21439
cvssv3.1 6.5 https://nvd.nist.gov/vuln/detail/CVE-2021-21439
Reference id Reference type URL
https://api.first.org/data/v1/epss?cve=CVE-2021-21439
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-21439
https://lists.debian.org/debian-lts-announce/2023/08/msg00040.html
https://otrs.com/release-notes/otrs-security-advisory-2021-09/
989992 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=989992
cpe:2.3:a:otrs:otrs:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:otrs:otrs:*:*:*:*:*:*:*:*
cpe:2.3:a:otrs:otrs:*:*:*:*:community:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:otrs:otrs:*:*:*:*:community:*:*:*
CVE-2021-21439 https://nvd.nist.gov/vuln/detail/CVE-2021-21439
No exploits are available.
Vector: AV:N/AC:M/Au:N/C:N/I:N/A:P Found at https://nvd.nist.gov/vuln/detail/CVE-2021-21439
Exploitability (E) Access Vector (AV) Access Complexity (AC) Authentication (Au) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

high

functional

unproven

proof_of_concept

not_defined

local

adjacent_network

network

high

medium

low

multiple

single

none

none

partial

complete

none

partial

complete

none

partial

complete
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2021-21439
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Exploit Prediction Scoring System (EPSS)
Percentile 0.65347
EPSS Score 0.00509
Published At July 31, 2025, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2025-07-31T10:16:51.649207+00:00 NVD Importer Import https://nvd.nist.gov/vuln/detail/CVE-2021-21439 37.0.0