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Vulnerability details: VCID-mmfc-us8q-xbha
Vulnerability ID VCID-mmfc-us8q-xbha
Aliases CVE-2021-29454
GHSA-29gp-2c3m-3j6m
Summary Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') Smarty is a template engine for PHP, facilitating the separation of presentation (HTML/CSS) from application logic. Template authors could run arbitrary PHP code by crafting a malicious math string. If a math string was passed through as user provided data to the math function, external users could run arbitrary PHP code by crafting a malicious math string.
Status Published
Exploitability 0.5
Weighted Severity 8.0
Risk 4.0
Affected and Fixed Packages Package Details
Weaknesses (3)
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
System Score Found at
epss 0.00643 https://api.first.org/data/v1/epss?cve=CVE-2021-29454
cvssv3.1_qr HIGH https://github.com/advisories/GHSA-29gp-2c3m-3j6m
cvssv3.1 8.1 https://github.com/FriendsOfPHP/security-advisories/blob/master/smarty/smarty/CVE-2021-29454.yaml
generic_textual HIGH https://github.com/FriendsOfPHP/security-advisories/blob/master/smarty/smarty/CVE-2021-29454.yaml
cvssv3.1 8.1 https://github.com/smarty-php/smarty
generic_textual HIGH https://github.com/smarty-php/smarty
cvssv3.1 8.1 https://github.com/smarty-php/smarty/commit/215d81a9fa3cd63d82fb3ab56ecaf97cf1e7db71
generic_textual HIGH https://github.com/smarty-php/smarty/commit/215d81a9fa3cd63d82fb3ab56ecaf97cf1e7db71
ssvc Track https://github.com/smarty-php/smarty/commit/215d81a9fa3cd63d82fb3ab56ecaf97cf1e7db71
cvssv3.1 8.1 https://github.com/smarty-php/smarty/releases/tag/v3.1.42
generic_textual HIGH https://github.com/smarty-php/smarty/releases/tag/v3.1.42
ssvc Track https://github.com/smarty-php/smarty/releases/tag/v3.1.42
cvssv3.1 8.1 https://github.com/smarty-php/smarty/releases/tag/v4.0.2
generic_textual HIGH https://github.com/smarty-php/smarty/releases/tag/v4.0.2
ssvc Track https://github.com/smarty-php/smarty/releases/tag/v4.0.2
cvssv3.1 8.1 https://github.com/smarty-php/smarty/security/advisories/GHSA-29gp-2c3m-3j6m
cvssv3.1_qr HIGH https://github.com/smarty-php/smarty/security/advisories/GHSA-29gp-2c3m-3j6m
generic_textual HIGH https://github.com/smarty-php/smarty/security/advisories/GHSA-29gp-2c3m-3j6m
ssvc Track https://github.com/smarty-php/smarty/security/advisories/GHSA-29gp-2c3m-3j6m
cvssv3.1 8.1 https://lists.debian.org/debian-lts-announce/2022/05/msg00005.html
generic_textual HIGH https://lists.debian.org/debian-lts-announce/2022/05/msg00005.html
ssvc Track https://lists.debian.org/debian-lts-announce/2022/05/msg00005.html
cvssv3.1 8.1 https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BRAJVDRGCIY5UZ2PQHKDTT7RMKG6WJQQ/
ssvc Track https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BRAJVDRGCIY5UZ2PQHKDTT7RMKG6WJQQ/
cvssv3.1 8.1 https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L777JIBIWJV34HS7LXPIDWASG7TT4LNI/
ssvc Track https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L777JIBIWJV34HS7LXPIDWASG7TT4LNI/
cvssv3.1 8.1 https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BRAJVDRGCIY5UZ2PQHKDTT7RMKG6WJQQ
generic_textual HIGH https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BRAJVDRGCIY5UZ2PQHKDTT7RMKG6WJQQ
cvssv3.1 8.1 https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/L777JIBIWJV34HS7LXPIDWASG7TT4LNI
generic_textual HIGH https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/L777JIBIWJV34HS7LXPIDWASG7TT4LNI
cvssv3.1 8.1 https://nvd.nist.gov/vuln/detail/CVE-2021-29454
generic_textual HIGH https://nvd.nist.gov/vuln/detail/CVE-2021-29454
cvssv3.1 8.1 https://packagist.org/packages/smarty/smarty
generic_textual HIGH https://packagist.org/packages/smarty/smarty
ssvc Track https://packagist.org/packages/smarty/smarty
cvssv3.1 8.1 https://security.gentoo.org/glsa/202209-09
generic_textual HIGH https://security.gentoo.org/glsa/202209-09
ssvc Track https://security.gentoo.org/glsa/202209-09
cvssv3.1 8.1 https://www.debian.org/security/2022/dsa-5151
generic_textual HIGH https://www.debian.org/security/2022/dsa-5151
ssvc Track https://www.debian.org/security/2022/dsa-5151
cvssv3.1 8.1 https://www.smarty.net/docs/en/language.function.math.tpl
generic_textual HIGH https://www.smarty.net/docs/en/language.function.math.tpl
ssvc Track https://www.smarty.net/docs/en/language.function.math.tpl
Reference id Reference type URL
https://api.first.org/data/v1/epss?cve=CVE-2021-29454
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-21408
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-29454
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-29221
https://github.com/FriendsOfPHP/security-advisories/blob/master/smarty/smarty/CVE-2021-29454.yaml
https://github.com/smarty-php/smarty
https://github.com/smarty-php/smarty/commit/215d81a9fa3cd63d82fb3ab56ecaf97cf1e7db71
https://github.com/smarty-php/smarty/releases/tag/v3.1.42
https://github.com/smarty-php/smarty/releases/tag/v4.0.2
https://lists.debian.org/debian-lts-announce/2022/05/msg00005.html
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BRAJVDRGCIY5UZ2PQHKDTT7RMKG6WJQQ
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BRAJVDRGCIY5UZ2PQHKDTT7RMKG6WJQQ/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/L777JIBIWJV34HS7LXPIDWASG7TT4LNI
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/L777JIBIWJV34HS7LXPIDWASG7TT4LNI/
https://packagist.org/packages/smarty/smarty
https://security.gentoo.org/glsa/202209-09
https://www.debian.org/security/2022/dsa-5151
https://www.smarty.net/docs/en/language.function.math.tpl
1010375 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1010375
BRAJVDRGCIY5UZ2PQHKDTT7RMKG6WJQQ https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BRAJVDRGCIY5UZ2PQHKDTT7RMKG6WJQQ/
CVE-2021-29454 https://nvd.nist.gov/vuln/detail/CVE-2021-29454
GHSA-29gp-2c3m-3j6m https://github.com/advisories/GHSA-29gp-2c3m-3j6m
GHSA-29gp-2c3m-3j6m https://github.com/smarty-php/smarty/security/advisories/GHSA-29gp-2c3m-3j6m
L777JIBIWJV34HS7LXPIDWASG7TT4LNI https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L777JIBIWJV34HS7LXPIDWASG7TT4LNI/
USN-5348-1 https://usn.ubuntu.com/5348-1/
USN-USN-5348-2 https://usn.ubuntu.com/USN-5348-2/
USN-USN-5348-3 https://usn.ubuntu.com/USN-5348-3/
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N Found at https://github.com/FriendsOfPHP/security-advisories/blob/master/smarty/smarty/CVE-2021-29454.yaml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

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Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N Found at https://github.com/smarty-php/smarty
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

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Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N Found at https://github.com/smarty-php/smarty/commit/215d81a9fa3cd63d82fb3ab56ecaf97cf1e7db71
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

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Vector: SSVCv2/E:N/A:N/T:T/P:M/B:A/M:M/D:T/2025-04-23T15:57:13Z/ Found at https://github.com/smarty-php/smarty/commit/215d81a9fa3cd63d82fb3ab56ecaf97cf1e7db71
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N Found at https://github.com/smarty-php/smarty/releases/tag/v3.1.42
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

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Vector: SSVCv2/E:N/A:N/T:T/P:M/B:A/M:M/D:T/2025-04-23T15:57:13Z/ Found at https://github.com/smarty-php/smarty/releases/tag/v3.1.42
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N Found at https://github.com/smarty-php/smarty/releases/tag/v4.0.2
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

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Vector: SSVCv2/E:N/A:N/T:T/P:M/B:A/M:M/D:T/2025-04-23T15:57:13Z/ Found at https://github.com/smarty-php/smarty/releases/tag/v4.0.2
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N Found at https://github.com/smarty-php/smarty/security/advisories/GHSA-29gp-2c3m-3j6m
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

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Vector: SSVCv2/E:N/A:N/T:T/P:M/B:A/M:M/D:T/2025-04-23T15:57:13Z/ Found at https://github.com/smarty-php/smarty/security/advisories/GHSA-29gp-2c3m-3j6m
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N Found at https://lists.debian.org/debian-lts-announce/2022/05/msg00005.html
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

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Vector: SSVCv2/E:N/A:N/T:T/P:M/B:A/M:M/D:T/2025-04-23T15:57:13Z/ Found at https://lists.debian.org/debian-lts-announce/2022/05/msg00005.html
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N Found at https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BRAJVDRGCIY5UZ2PQHKDTT7RMKG6WJQQ/
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

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Vector: SSVCv2/E:N/A:N/T:T/P:M/B:A/M:M/D:T/2025-04-23T15:57:13Z/ Found at https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BRAJVDRGCIY5UZ2PQHKDTT7RMKG6WJQQ/
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N Found at https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L777JIBIWJV34HS7LXPIDWASG7TT4LNI/
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

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Vector: SSVCv2/E:N/A:N/T:T/P:M/B:A/M:M/D:T/2025-04-23T15:57:13Z/ Found at https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L777JIBIWJV34HS7LXPIDWASG7TT4LNI/
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N Found at https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BRAJVDRGCIY5UZ2PQHKDTT7RMKG6WJQQ
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

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Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N Found at https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/L777JIBIWJV34HS7LXPIDWASG7TT4LNI
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

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Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2021-29454
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

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Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N Found at https://packagist.org/packages/smarty/smarty
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

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Vector: SSVCv2/E:N/A:N/T:T/P:M/B:A/M:M/D:T/2025-04-23T15:57:13Z/ Found at https://packagist.org/packages/smarty/smarty
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N Found at https://security.gentoo.org/glsa/202209-09
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

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Vector: SSVCv2/E:N/A:N/T:T/P:M/B:A/M:M/D:T/2025-04-23T15:57:13Z/ Found at https://security.gentoo.org/glsa/202209-09
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N Found at https://www.debian.org/security/2022/dsa-5151
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

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Vector: SSVCv2/E:N/A:N/T:T/P:M/B:A/M:M/D:T/2025-04-23T15:57:13Z/ Found at https://www.debian.org/security/2022/dsa-5151
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N Found at https://www.smarty.net/docs/en/language.function.math.tpl
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

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Vector: SSVCv2/E:N/A:N/T:T/P:M/B:A/M:M/D:T/2025-04-23T15:57:13Z/ Found at https://www.smarty.net/docs/en/language.function.math.tpl
Exploit Prediction Scoring System (EPSS)
Percentile 0.71031
EPSS Score 0.00643
Published At June 4, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-06-02T04:40:54.539113+00:00 GitLab Importer Import https://gitlab.com/gitlab-org/advisories-community/-/blob/main/packagist/smarty/smarty/CVE-2021-29454.yml 38.6.0