Drupal Core Remote Code Execution
CVE-2018-7600 is a critical-severity improper input validation vulnerability in Drupal before 7.58, 8.x before 8.3.9, 8.4.x before 8.4.6, and 8.5.x before 8.5.1, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. CISA added it to the Known Exploited Vulnerabilities catalogue on November 3, 2021, which means attacks have been observed in the wild, including in ransomware campaigns.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Update Drupal to 8.3.9 or 8.4.6 or 8.5.1, whichever matches your release line, or a later version.
- CISA's required action: Apply updates per vendor instructions.
- Read the advisory on groups.drupal.org for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Drupal before 7.58, 8.x before 8.3.9, 8.4.x before 8.4.6, and 8.5.x before 8.5.1 | Drupal before 7.58, 8.x before 8.3.9, 8.4.x before 8.4.6, and 8.5.x before 8.5.1 | Not specified in the record | Not stated |
| Drupal | Drupal | 7.57 and earlier; 8.0.0 up to, but not including, 8.3.9; 8.4.0 up to, but not including, 8.4.6; 8.5.0 up to, but not including, 8.5.1 | 8.3.9, 8.4.6, 8.5.1 |
| Debian | Debian Linux | 7.0; 8.0; 9.0 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.8 | Critical | NVD |
| CVSS 3.1 | 9.8 | Critical | CISA (ADP) |
| CVSS 2.0 | 7.5 | High | NVD |
Official description
Drupal before 7.58, 8.x before 8.3.9, 8.4.x before 8.4.6, and 8.5.x before 8.5.1 allows remote attackers to execute arbitrary code because of an issue affecting multiple subsystems with default or common module configurations.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
How developers prevent this class of flaw
- Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build recognizers for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of allowing parser code to be scattered throughout the program, where it could be subject to errors or inconsistencies that create weaknesses.
- Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
- Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
Timeline
- CVE record published.
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- CISA published its SSVC assessment (exploitation: active, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- github.com/g0rx/CVE-2018-7600-Drupal-RCEThird Party Advisory
Third-party and government advisories
- blog.appsecco.com/remote-code-execution-with-drupal-core-sa-core-2018-002-95e6ecc0c714Third Party Advisory
- github.com/a2u/CVE-2018-7600Third Party Advisory
- lists.debian.org/debian-lts-announce/2018/03/msg00028.htmlThird Party Advisory
- twitter.com/arancaytar/status/979090719003627521Third Party Advisory
- debian.org/security/2018/dsa-4156Third Party Advisory
- synology.com/support/security/Synology_SA_18_17Third Party Advisory
- tenable.com/blog/critical-drupal-core-vulnerability-what-you-need-to-knowThird Party Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-7600US Government Resource
Technical write-ups (may include proof of concept)
- research.checkpoint.com/uncovering-drupalgeddon-2/Exploit, Third Party Advisory
- exploit-db.com/exploits/44448/Exploit, Third Party Advisory, VDB Entry
- exploit-db.com/exploits/44449/Exploit, Third Party Advisory, VDB Entry
- exploit-db.com/exploits/44482/Exploit, Third Party Advisory, VDB Entry
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