CVE-2024-28859 is a medium-severity (CVSS 5) Deserialization of Untrusted Data vulnerability in friendsofsymfony1/symfony1. A fix is available for friendsofsymfony1/symfony1 — see the affected versions and patch details below.
Gadget chain in Symfony 1 due to vulnerable Swift Mailer dependency
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2024-28859.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2024-28859 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,238 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
friendsofsymfony1/symfony1🐘friendsofsymfony1/swiftmailer🐘friendsofsymfony1/swiftmailer🐘swiftmailer/swiftmailerReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Symfony1 is a community fork of symfony 1.4 with DIC, form enhancements, latest Swiftmailer, better performance, composer compatible and PHP 8 support. Symfony 1 has a gadget chain due to vulnerable Swift Mailer dependency that would enable an attacker to get remote code execution if a developer unserialize user input in his project. This vulnerability present no direct threat but is a vector that will enable remote code execution if a developper deserialize user untrusted data. Symfony 1 depends on Swift Mailer which is bundled by default in vendor directory in the default installation since 1.3.0. Swift Mailer classes implement some __destruct() methods. These methods are called when php destroys the object in memory. However, it is possible to include any object type in $this->_keys to make PHP access to another array/object properties than intended by the developer. In particular, it is possible to abuse the array access which is triggered on foreach($this->_keys ...) for any class implementing ArrayAccess interface. This may allow an attacker to execute any PHP command which leads to remote code execution. This issue has been addressed in version 1.5.18. Users are advised to upgrade. There are no known workarounds for this vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | friendsofsymfony1/symfony1 | ≥ 1.3.0&&< 1.5.18 | 1.5.18composer require friendsofsymfony1/symfony1:^1.5.18 |
| 🐘Packagist | friendsofsymfony1/swiftmailer | ≥ 4.0.0&&< 5.4.13 | 5.4.13composer require friendsofsymfony1/swiftmailer:^5.4.13 |
| 🐘Packagist | friendsofsymfony1/swiftmailer | ≥ 6.0.0&&< 6.2.5 | 6.2.5composer require friendsofsymfony1/swiftmailer:^6.2.5 |
| 🐘Packagist | swiftmailer/swiftmailer | ≥ 4.0.0&&< 6.2.5 | 6.2.5composer require swiftmailer/swiftmailer:^6.2.5 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for friendsofsymfony1/symfony1, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update friendsofsymfony1/symfony1 to 1.5.18 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-28859 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2024-28859 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2024-28859. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2024-28859 in your dependencies?
O3 Security finds CVE-2024-28859 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.