Security readout for executives and security teams
Plain-English summary
A flaw in ImpressCMS 1.4.2, an open-source content management system, lets an attacker who already has admin-level access plant malicious code on the website and run any command on the server. In practical terms, a compromised or rogue admin account can fully take over the site and the underlying host.
Executive priority
Treat as a high-priority patch or mitigation item for any business unit that operates ImpressCMS 1.4.2. Because exploitation requires admin login, the immediate fire is smaller than an unauthenticated RCE, but a single compromised admin account leads to full site and likely server takeover, which is a material brand and data risk.
Technical view
CVE-2021-47938 is a CWE-94 code injection in ImpressCMS 1.4.2's autotasks admin module. An authenticated user POSTing to /modules/system/admin.php?fct=autotasks&op=mod with a crafted sat_code parameter causes the application to write attacker-controlled PHP to disk, producing a webshell that executes commands supplied via GET parameters. CVSS 3.1 base score is 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).
Likely exposure
Limited to organizations running ImpressCMS 1.4.2 with internet-reachable admin interfaces. Exposure rises sharply where admin credentials are weak, reused, or shared, or where the admin panel is not network-restricted. No CPE list was published, so inventory must be confirmed manually.
Exploitation context
No CISA KEV listing and no confirmed in-the-wild exploitation cited in the bundle. However, a public proof-of-concept exists at ExploitDB entry 50298 and a VulnCheck advisory documents the issue, so the technical barrier to weaponization is low for any actor who can obtain administrator credentials.
Researcher notes
Root cause is unsafe handling of the sat_code field in the autotasks "mod" operation, which is concatenated into a generated PHP task file rather than validated or stored as inert data (CWE-94). The ExploitDB PoC demonstrates the file-write-then-GET-execute pattern. No fixed version is asserted in the bundle, so confirm patch status directly with the ImpressCMS project before declaring remediation complete. Bundle lists no CPE strings, so asset matching must be done by version string.
Mitigation direction
- Inventory all ImpressCMS instances and confirm whether any run version 1.4.2.
- Check the ImpressCMS project site for an upgraded release or vendor advisory and apply it.
- Restrict /modules/system/admin.php to trusted IPs or VPN until patched.
- Rotate administrator credentials and enforce multi-factor authentication on admin accounts.
- Review web root for unexpected PHP files created near autotasks activity and remove webshells.
- Monitor web server logs for POSTs to admin.php with fct=autotasks and unusual GET parameters.
Validation and detection
- Confirm the running ImpressCMS version against the 1.4.2 affected release listed in the advisory.
- In a controlled lab, verify whether your build still writes attacker-supplied sat_code to disk via the autotasks endpoint.
- Audit administrator accounts and recent sessions for unauthorized logins.
- Search the filesystem and web logs for suspicious .php files matching autotask output patterns.
- Re-test after applying vendor guidance to confirm the autotasks form no longer accepts raw PHP.
- Review WAF and EDR telemetry for prior exploitation indicators referenced in the VulnCheck advisory.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-94: Code execution behavior lookup
Code execution and unsafe deserialization weaknesses often justify reviewing execution behavior and process telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-47938 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H2.85.9VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N——VulnCheckVulnerability scoring details
Base CVSS 4.0 score
8.7HighVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- ExploitDB-50298CVE reference, VulnCheck · exploit
- Official Product HomepageCVE reference, VulnCheck · product
- Product ReferenceCVE reference, VulnCheck · product
- VulnCheck Advisory: ImpressCMS 1.4.2 Remote Code Execution via AutotasksCVE reference, VulnCheck · third-party-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Control of Generation of Code ('Code Injection')
Improper Control of Generation of Code ('Code Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.