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Vulnerability details: VCID-x9we-vp2y-9qdh
Vulnerability ID VCID-x9we-vp2y-9qdh
Aliases CVE-2021-29476
GHSA-52qp-jpq7-6c54
Summary Insecure Deserialization of untrusted data in rmccue/requests ### Impact Unserialization of untrusted data. ### Patches The issue has been patched and users of `Requests` 1.6.0, 1.6.1 and 1.7.0 should update to version 1.8.0. ### References Publications about the vulnerability: * https://dannewitz.ninja/posts/php-unserialize-object-injection-yet-another-stars-rating-wordpress * https://github.com/ambionics/phpggc/issues/52 * https://blog.detectify.com/2019/07/23/improving-wordpress-plugin-security/ * https://i.blackhat.com/us-18/Thu-August-9/us-18-Thomas-Its-A-PHP-Unserialization-Vulnerability-Jim-But-Not-As-We-Know-It.pdf * https://cdn2.hubspot.net/hubfs/3853213/us-18-Thomas-It%27s-A-PHP-Unserialization-Vulnerability-Jim-But-Not-As-We-....pdf * https://2018.zeronights.ru/wp-content/uploads/materials/9%20ZN2018%20WV%20-%20PHP%20unserialize.pdf * https://medium.com/@knownsec404team/extend-the-attack-surface-of-php-deserialization-vulnerability-via-phar-d6455c6a1066#3c0f Originally fixed in WordPress 5.5.2: * https://github.com/WordPress/wordpress-develop/commit/add6bedf3a53b647d0ebda2970057912d3cd79d3 * https://wordpress.org/news/2020/10/wordpress-5-5-2-security-and-maintenance-release/ Related Security Advisories: * https://cve.mitre.org/cgi-bin/cvename.cgi?name=2020-28032 * https://nvd.nist.gov/vuln/detail/CVE-2020-28032 Notification to the Requests repo including a fix in: * https://github.com/rmccue/Requests/pull/421 and * https://github.com/rmccue/Requests/pull/422 ### For more information If you have any questions or comments about this advisory: * Open an issue in [Request](https://github.com/WordPress/Requests/)
Status Published
Exploitability 0.5
Weighted Severity 9.0
Risk 4.5
Affected and Fixed Packages Package Details
Weaknesses (3)
CWE-502 Deserialization of Untrusted Data
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
cvssv3.1 9.8 https://2018.zeronights.ru/wp-content/uploads/materials/9%20ZN2018%20WV%20-%20PHP%20unserialize.pdf
generic_textual CRITICAL https://2018.zeronights.ru/wp-content/uploads/materials/9%20ZN2018%20WV%20-%20PHP%20unserialize.pdf
epss 0.02219 https://api.first.org/data/v1/epss?cve=CVE-2021-29476
epss 0.02219 https://api.first.org/data/v1/epss?cve=CVE-2021-29476
epss 0.02219 https://api.first.org/data/v1/epss?cve=CVE-2021-29476
epss 0.02219 https://api.first.org/data/v1/epss?cve=CVE-2021-29476
epss 0.02219 https://api.first.org/data/v1/epss?cve=CVE-2021-29476
epss 0.02219 https://api.first.org/data/v1/epss?cve=CVE-2021-29476
epss 0.02219 https://api.first.org/data/v1/epss?cve=CVE-2021-29476
epss 0.02219 https://api.first.org/data/v1/epss?cve=CVE-2021-29476
epss 0.02219 https://api.first.org/data/v1/epss?cve=CVE-2021-29476
epss 0.02219 https://api.first.org/data/v1/epss?cve=CVE-2021-29476
epss 0.02219 https://api.first.org/data/v1/epss?cve=CVE-2021-29476
epss 0.02219 https://api.first.org/data/v1/epss?cve=CVE-2021-29476
epss 0.02219 https://api.first.org/data/v1/epss?cve=CVE-2021-29476
epss 0.02219 https://api.first.org/data/v1/epss?cve=CVE-2021-29476
epss 0.02219 https://api.first.org/data/v1/epss?cve=CVE-2021-29476
cvssv3.1 9.8 https://blog.detectify.com/2019/07/23/improving-wordpress-plugin-security
generic_textual CRITICAL https://blog.detectify.com/2019/07/23/improving-wordpress-plugin-security
cvssv3.1 9.8 https://cdn2.hubspot.net/hubfs/3853213/us-18-Thomas-It%27s-A-PHP-Unserialization-Vulnerability-Jim-But-Not-As-We-....pdf
generic_textual CRITICAL https://cdn2.hubspot.net/hubfs/3853213/us-18-Thomas-It%27s-A-PHP-Unserialization-Vulnerability-Jim-But-Not-As-We-....pdf
cvssv3.1 9.8 https://dannewitz.ninja/posts/php-unserialize-object-injection-yet-another-stars-rating-wordpress
generic_textual CRITICAL https://dannewitz.ninja/posts/php-unserialize-object-injection-yet-another-stars-rating-wordpress
cvssv3.1_qr CRITICAL https://github.com/advisories/GHSA-52qp-jpq7-6c54
cvssv3.1 9.8 https://github.com/ambionics/phpggc/issues/52
generic_textual CRITICAL https://github.com/ambionics/phpggc/issues/52
cvssv3.1 9.8 https://github.com/FriendsOfPHP/security-advisories/blob/master/rmccue/requests/CVE-2021-29476.yaml
generic_textual CRITICAL https://github.com/FriendsOfPHP/security-advisories/blob/master/rmccue/requests/CVE-2021-29476.yaml
cvssv3.1 9.8 https://github.com/rmccue/Requests/pull/421
generic_textual CRITICAL https://github.com/rmccue/Requests/pull/421
cvssv3.1 9.8 https://github.com/WordPress/Requests/security/advisories/GHSA-52qp-jpq7-6c54
cvssv3.1_qr CRITICAL https://github.com/WordPress/Requests/security/advisories/GHSA-52qp-jpq7-6c54
generic_textual CRITICAL https://github.com/WordPress/Requests/security/advisories/GHSA-52qp-jpq7-6c54
cvssv3.1 9.8 https://github.com/WordPress/wordpress-develop/commit/add6bedf3a53b647d0ebda2970057912d3cd79d3
generic_textual CRITICAL https://github.com/WordPress/wordpress-develop/commit/add6bedf3a53b647d0ebda2970057912d3cd79d3
cvssv3.1 9.8 https://i.blackhat.com/us-18/Thu-August-9/us-18-Thomas-Its-A-PHP-Unserialization-Vulnerability-Jim-But-Not-As-We-Know-It.pdf
generic_textual CRITICAL https://i.blackhat.com/us-18/Thu-August-9/us-18-Thomas-Its-A-PHP-Unserialization-Vulnerability-Jim-But-Not-As-We-Know-It.pdf
cvssv3.1 9.8 https://medium.com/@knownsec404team/extend-the-attack-surface-of-php-deserialization-vulnerability-via-phar-d6455c6a1066#3c0f
generic_textual CRITICAL https://medium.com/@knownsec404team/extend-the-attack-surface-of-php-deserialization-vulnerability-via-phar-d6455c6a1066#3c0f
cvssv2 7.5 https://nvd.nist.gov/vuln/detail/CVE-2021-29476
cvssv3.1 9.8 https://nvd.nist.gov/vuln/detail/CVE-2021-29476
generic_textual CRITICAL https://nvd.nist.gov/vuln/detail/CVE-2021-29476
cvssv3.1 9.8 https://wordpress.org/news/2020/10/wordpress-5-5-2-security-and-maintenance-release
generic_textual CRITICAL https://wordpress.org/news/2020/10/wordpress-5-5-2-security-and-maintenance-release
Reference id Reference type URL
https://2018.zeronights.ru/wp-content/uploads/materials/9%20ZN2018%20WV%20-%20PHP%20unserialize.pdf
https://api.first.org/data/v1/epss?cve=CVE-2021-29476
https://blog.detectify.com/2019/07/23/improving-wordpress-plugin-security
https://blog.detectify.com/2019/07/23/improving-wordpress-plugin-security/
https://cdn2.hubspot.net/hubfs/3853213/us-18-Thomas-It%27s-A-PHP-Unserialization-Vulnerability-Jim-But-Not-As-We-....pdf
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-29476
https://dannewitz.ninja/posts/php-unserialize-object-injection-yet-another-stars-rating-wordpress
https://github.com/ambionics/phpggc/issues/52
https://github.com/FriendsOfPHP/security-advisories/blob/master/rmccue/requests/CVE-2021-29476.yaml
https://github.com/rmccue/Requests/pull/421
https://github.com/WordPress/Requests/security/advisories/GHSA-52qp-jpq7-6c54
https://github.com/WordPress/wordpress-develop/commit/add6bedf3a53b647d0ebda2970057912d3cd79d3
https://i.blackhat.com/us-18/Thu-August-9/us-18-Thomas-Its-A-PHP-Unserialization-Vulnerability-Jim-But-Not-As-We-Know-It.pdf
https://medium.com/@knownsec404team/extend-the-attack-surface-of-php-deserialization-vulnerability-via-phar-d6455c6a1066#3c0f
https://nvd.nist.gov/vuln/detail/CVE-2021-29476
https://wordpress.org/news/2020/10/wordpress-5-5-2-security-and-maintenance-release
https://wordpress.org/news/2020/10/wordpress-5-5-2-security-and-maintenance-release/
cpe:2.3:a:wordpress:requests:1.6.0:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:wordpress:requests:1.6.0:*:*:*:*:*:*:*
cpe:2.3:a:wordpress:requests:1.6.1:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:wordpress:requests:1.6.1:*:*:*:*:*:*:*
cpe:2.3:a:wordpress:requests:1.7.0:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:wordpress:requests:1.7.0:*:*:*:*:*:*:*
GHSA-52qp-jpq7-6c54 https://github.com/advisories/GHSA-52qp-jpq7-6c54
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://2018.zeronights.ru/wp-content/uploads/materials/9%20ZN2018%20WV%20-%20PHP%20unserialize.pdf
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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high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://blog.detectify.com/2019/07/23/improving-wordpress-plugin-security
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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low

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high

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Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://cdn2.hubspot.net/hubfs/3853213/us-18-Thomas-It%27s-A-PHP-Unserialization-Vulnerability-Jim-But-Not-As-We-....pdf
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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high

none

required

unchanged

changed

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low

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Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://dannewitz.ninja/posts/php-unserialize-object-injection-yet-another-stars-rating-wordpress
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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none

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required

unchanged

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Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://github.com/ambionics/phpggc/issues/52
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:L/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://github.com/FriendsOfPHP/security-advisories/blob/master/rmccue/requests/CVE-2021-29476.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

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

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low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://github.com/rmccue/Requests/pull/421
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:L/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://github.com/WordPress/Requests/security/advisories/GHSA-52qp-jpq7-6c54
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:L/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://github.com/WordPress/wordpress-develop/commit/add6bedf3a53b647d0ebda2970057912d3cd79d3
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:L/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://i.blackhat.com/us-18/Thu-August-9/us-18-Thomas-Its-A-PHP-Unserialization-Vulnerability-Jim-But-Not-As-We-Know-It.pdf
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:L/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://medium.com/@knownsec404team/extend-the-attack-surface-of-php-deserialization-vulnerability-via-phar-d6455c6a1066#3c0f
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: AV:N/AC:L/Au:N/C:P/I:P/A:P Found at https://nvd.nist.gov/vuln/detail/CVE-2021-29476
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:N/S:U/C:H/I:H/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2021-29476
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:L/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://wordpress.org/news/2020/10/wordpress-5-5-2-security-and-maintenance-release
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
Exploit Prediction Scoring System (EPSS)
Percentile 0.83821
EPSS Score 0.02219
Published At Aug. 16, 2025, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2025-07-31T08:48:57.005548+00:00 GithubOSV Importer Import https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/04/GHSA-52qp-jpq7-6c54/GHSA-52qp-jpq7-6c54.json 37.0.0