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Vulnerability details: VCID-s3ep-tgah-aud1
Vulnerability ID VCID-s3ep-tgah-aud1
Aliases CVE-2019-18887
GHSA-q8hg-pf8v-cxrv
Summary Symfony Http-Kernel has non-constant time comparison in UriSigner When checking the signature of an URI (an ESI fragment URL for instance), the URISigner did not used a constant time string comparison function, resulting in a potential remote timing attack vulnerability.
Status Published
Exploitability 0.5
Weighted Severity 8.0
Risk 4.0
Affected and Fixed Packages Package Details
Weaknesses (3)
CWE-203 Observable Discrepancy
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
System Score Found at
epss 0.00813 https://api.first.org/data/v1/epss?cve=CVE-2019-18887
cvssv3.1_qr HIGH https://github.com/advisories/GHSA-q8hg-pf8v-cxrv
cvssv3.1 8.1 https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/http-kernel/CVE-2019-18887.yaml
generic_textual HIGH https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/http-kernel/CVE-2019-18887.yaml
cvssv3.1 8.1 https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2019-18887.yaml
generic_textual HIGH https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2019-18887.yaml
cvssv3.1 8.1 https://github.com/symfony/symfony/releases/tag/v4.3.8
generic_textual HIGH https://github.com/symfony/symfony/releases/tag/v4.3.8
cvssv3.1 8.1 https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DZNXRVHDQBNZQUCNRVZICPPBFRAUWUJX
generic_textual HIGH https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DZNXRVHDQBNZQUCNRVZICPPBFRAUWUJX
cvssv3.1 8.1 https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UED22BOXTL2SSFMGYKA64ZFHGLLJG3EA
generic_textual HIGH https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UED22BOXTL2SSFMGYKA64ZFHGLLJG3EA
cvssv3.1 8.1 https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VXEAOEANNIVYANTMOJ42NKSU6BGNBULZ
generic_textual HIGH https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VXEAOEANNIVYANTMOJ42NKSU6BGNBULZ
cvssv3.1 8.1 https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DZNXRVHDQBNZQUCNRVZICPPBFRAUWUJX
generic_textual HIGH https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DZNXRVHDQBNZQUCNRVZICPPBFRAUWUJX
cvssv3.1 8.1 https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UED22BOXTL2SSFMGYKA64ZFHGLLJG3EA
generic_textual HIGH https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UED22BOXTL2SSFMGYKA64ZFHGLLJG3EA
cvssv3.1 8.1 https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VXEAOEANNIVYANTMOJ42NKSU6BGNBULZ
generic_textual HIGH https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VXEAOEANNIVYANTMOJ42NKSU6BGNBULZ
cvssv3.1 8.1 https://nvd.nist.gov/vuln/detail/CVE-2019-18887
generic_textual HIGH https://nvd.nist.gov/vuln/detail/CVE-2019-18887
cvssv3.1 8.1 https://symfony.com/blog/cve-2019-18887-use-constant-time-comparison-in-urisigner
generic_textual HIGH https://symfony.com/blog/cve-2019-18887-use-constant-time-comparison-in-urisigner
cvssv3.1 8.1 https://symfony.com/blog/symfony-4-3-8-released
generic_textual HIGH https://symfony.com/blog/symfony-4-3-8-released
cvssv3.1 8.1 https://symfony.com/cve-2019-18887
generic_textual HIGH https://symfony.com/cve-2019-18887
Reference id Reference type URL
https://api.first.org/data/v1/epss?cve=CVE-2019-18887
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-18887
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-18888
https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/http-kernel/CVE-2019-18887.yaml
https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2019-18887.yaml
https://github.com/symfony/symfony/releases/tag/v4.3.8
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DZNXRVHDQBNZQUCNRVZICPPBFRAUWUJX
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DZNXRVHDQBNZQUCNRVZICPPBFRAUWUJX/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UED22BOXTL2SSFMGYKA64ZFHGLLJG3EA
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UED22BOXTL2SSFMGYKA64ZFHGLLJG3EA/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VXEAOEANNIVYANTMOJ42NKSU6BGNBULZ
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VXEAOEANNIVYANTMOJ42NKSU6BGNBULZ/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DZNXRVHDQBNZQUCNRVZICPPBFRAUWUJX
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DZNXRVHDQBNZQUCNRVZICPPBFRAUWUJX/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UED22BOXTL2SSFMGYKA64ZFHGLLJG3EA
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UED22BOXTL2SSFMGYKA64ZFHGLLJG3EA/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VXEAOEANNIVYANTMOJ42NKSU6BGNBULZ
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VXEAOEANNIVYANTMOJ42NKSU6BGNBULZ/
https://nvd.nist.gov/vuln/detail/CVE-2019-18887
https://symfony.com/blog/cve-2019-18887-use-constant-time-comparison-in-urisigner
https://symfony.com/blog/symfony-4-3-8-released
https://symfony.com/cve-2019-18887
GHSA-q8hg-pf8v-cxrv https://github.com/advisories/GHSA-q8hg-pf8v-cxrv
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/http-kernel/CVE-2019-18887.yaml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

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Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2019-18887.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:H/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://github.com/symfony/symfony/releases/tag/v4.3.8
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:H/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DZNXRVHDQBNZQUCNRVZICPPBFRAUWUJX
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

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Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UED22BOXTL2SSFMGYKA64ZFHGLLJG3EA
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

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Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VXEAOEANNIVYANTMOJ42NKSU6BGNBULZ
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

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Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DZNXRVHDQBNZQUCNRVZICPPBFRAUWUJX
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

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required

unchanged

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Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UED22BOXTL2SSFMGYKA64ZFHGLLJG3EA
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

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Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VXEAOEANNIVYANTMOJ42NKSU6BGNBULZ
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

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low

none

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Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2019-18887
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

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none
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://symfony.com/blog/cve-2019-18887-use-constant-time-comparison-in-urisigner
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
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://symfony.com/blog/symfony-4-3-8-released
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

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low

none
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://symfony.com/cve-2019-18887
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

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none

required

unchanged

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Exploit Prediction Scoring System (EPSS)
Percentile 0.73222
EPSS Score 0.00813
Published At June 30, 2025, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2025-07-01T12:24:49.618338+00:00 GithubOSV Importer Import https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2022/03/GHSA-q8hg-pf8v-cxrv/GHSA-q8hg-pf8v-cxrv.json 36.1.3