Symfony Cross-Site Request Forgery vulnerability in the Web Profiler
All 2.0.X, 2.1.X, 2.2.X, 2.3.X, 2.4.X, and 2.5.X versions of the Symfony WebProfiler bundle are affected by this security issue.
This issue has been fixed in Symfony 2.3.19, 2.4.9, and 2.5.4. Note that no fixes are provided for Symfony 2.0, 2.1, and 2.2 as they are not maintained anymore.
Description
The Symfony Web Profiler is a great development tool, but it should not be enabled on production servers. If it is enabled in production, it must be properly secured so that only authorized people have access to it. Developers must be very cautious about this as the Web Profiler gives many sensitive information about a Symfony project and any attackers can exploit many of them. Just to name a few sensitive information: user logins, user cookies, executed SQL statements, ...
That being said, the import/export feature of the web profiler is exploitable even if the Web Profiler is secured as the form to import a profiler is not protected against CSRF attacks. Combined with the fact that profiles are imported as a PHP serialized string, it makes your application vulnerable to code injection.
Resolution
As the import/export feature of the Web Profiler is not that useful, and because PHP
serialize/unserialize functions have a long history of vulnerabilities, I decided to remove this feature from the Web interface and move it as CLI commands.
If you were relying on this feature, you now need to use the profiler:import and profiler:export Symfony commands provided by the WebProfiler bundle from the command line interface.
Those commands are not enabled by default and must be activated explicitly. For Symfony 2.4+, you can import them in your app/config.yml configuration file:
import:
- { resource: "%kernel.root_dir%/../vendor/symfony/symfony/src/Symfony/Bundle/WebProfilerBundle/Resources/config/commands.xml" }
For Symfony 2.3, you can use the following snippet of code in
app/console:
$kernel = new AppKernel($env, $debug);
$application = new Application($kernel);
if ($kernel->getContainer()->has('profiler')) {
$profiler = $kernel->getContainer()->get('profiler');
$application->add(new ImportCommand($profiler));
$application->add(new ExportCommand($profiler));
}
$application->run($input);
At this point, I want to reiterate that you should never enable the Symfony Web Profiler on your production servers as this is a development tool. And if you need to enable it, double-check that it is properly secured.
The patch for this issue is available here: https://github.com/symfony/symfony/pull/11832
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (8.1): severity, escalated by confirmed exploitation. This CVE's 8.1 is its impact severity (EG Severity), not escalated.
- EG Severity
- 8.1 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- Unknown (no EPSS on record)Unknown, not low: FIRST has published no EPSS probability for this CVE.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it