CVE-2024-34716: PrestaShop cross-site scripting via customer contact form in FO, through file upload

Should you act?

High exploit likelihood

EPSS ranks it in the top 5% of all CVEs for likely exploitation in the next 30 days. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 56.4%, percentile 99: FIRST’s model estimates a 56.4% chance of exploitation activity in the next 30 days, higher than 99% of all scored CVEs (very high). EPSS is a probability, not a verdict.
• Needs a user to click or open something. Phishing makes that realistic, but it is not wormable.
• Only applies if your dependency tree includes prestashop/prestashop (Composer (PHP)) >= 8.1.0, < 8.1.6, fixed in 8.1.6. Check your lockfile, including transitive dependencies.

What it is

PrestaShop is an open source e-commerce web application. A cross-site scripting (XSS) vulnerability that only affects PrestaShops with customer-thread feature flag enabled is present starting from PrestaShop 8.1.0 and prior to PrestaShop 8.1.6. When the customer thread feature flag is enabled through the front-office contact form, a hacker can upload a malicious file containing an XSS that will be executed when an admin opens the attached file in back office. The script injected can access the session and the security token, which allows it to perform any authenticated action in the scope of the administrator's right. This vulnerability is patched in 8.1.6. A workaround is to disable the customer-thread feature-flag.

From the GitHub advisory

Impact Only PrestaShops with customer-thread feature flag enabled are impacted, starting from PrestaShop 8.1.0.

The impact is substantial, when the customer thread feature flag is enabled, through the front-office contact form, a hacker can upload a malicious file containing an XSS that will be executed when an admin opens the attached file in back office.

Consequence: the script injected can access the session and the security token, which allows it to perform any authenticated action in the scope of the administrator's right.

Patches This vulnerability is patched in 8.1.6.

Workarounds As long as you have not upgraded to 8.1.6, a simple workaround is to disable the customer-thread feature-flag.

Weakness type: CWE-79.

Product: prestashop/prestashop (Composer (PHP)) · Assigned by: GitHub_M · Published: 2024-05-14

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: none (no login)
• User interaction: required (a user must click/open something)
• Scope: changed (can affect other components)

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 56.45% probability of exploitation activity in the next 30 days; percentile 99.

Timeline

• 2024-05-14 — CVE record published by GitHub_M
• 2024-05-14 — GitHub-reviewed advisory GHSA-45vm-3j38-7p78 published (critical)
• 2024-08-02 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-45vm-3j38-7p78 github.com
2. CVE.org record CVE-2024-34716 cve.org
3. NVD entry CVE-2024-34716 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com

Critical Composer (PHP) advisories · Today’s Security Digest