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CVE-2021-35210

Public exploit available. Not confirmed exploited in the wild yet. Fixed in 4.9.16.

CVSS 3.16.1MediumEPSS percentile54th0.7% chance in 30 daysCISA KEVNot listedNo confirmed exploitation
Public exploit: 2 sourcesFix4.9.16Upgrade to this build

Published Updated Sources: CVE.org, NVD, GitHub

NVD CVE.org

What to do

Find your product and version, then upgrade to the build on the right.

  • Packagist contao/core-bundleAffected: ≥ 4.5.0, < 4.9.16Upgrade to: 4.9.16Stated by: GitHub advisory
  • Packagist contao/contaoAffected: ≥ 4.5.0, < 4.9.16Upgrade to: 4.9.16Stated by: GitHub advisory
  • ContaoAffected: ≥ 4.5.0, < 4.9.16Upgrade to: 4.9.16Stated by: NVD

Versions as the sources state them. Full version matrix after sign-in

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What it is

From the CVE record

Contao 4.5.x through 4.9.x before 4.9.16, and 4.10.x through 4.11.x before 4.11.5, allows XSS. It is possible to inject code into the tl_log table that will be executed in the browser when the system log is called in the back end.

In plain language

No plain-language summary for this CVE yet.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS54th
Public exploit
CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

2 sources with a proof of concept or module.

Exploit links, PoCs and Metasploit modules after sign-in
EPSS

0.7% chance of exploitation activity in the next 30 days, which ranks it in the 54th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

The patch came 471 days before any public exploit.

  1. Public exploit / PoCsource: github-poc
  2. Patch availablerecord updated
  3. Publishedweakness classified, att&ck mapped

Affected products

And 1 more affected product. See all after sign-in

Technical detail

CVSS 3.1 vector

Open in the CVSS calculator

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Scored 6.1 by NVD.

How it is reached

  • Attack Vector NetworkExploitable remotely over the network without any special conditions
  • Attack Complexity LowNo special conditions — the attack can be reliably reproduced
  • Privileges Required NoneNo authentication required — anyone can exploit this
  • User Interaction RequiredA user must click a link, open a file, or perform some action

Scope

  • Scope ChangedThe exploit can affect other components (e.g. sandbox escape, host compromise from VM)

Impact if exploited

  • Confidentiality LowSome restricted information is disclosed, but limited in scope
  • Integrity LowData modification is possible but limited in scope or consequence
  • Availability NoneNo availability impact

Weaknesses

ATT&CK techniques

Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.

Sources

References in the record

And 3 more references. See all after sign-in

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We'll flag the next CVE, public exploit or patch for Contao/core-bundle, not every advisory. This one: public exploit.