Published:2020/03/24  Last Updated:2020/03/24

mailform vulnerable to PHP code execution


mailform provided by contains a PHP code execution vulnerability.

Vendor Information


Product name and version: mailform version 1.04


mailform provided by is a PHP script providing a mail form function to a website.
mailform contains a PHP code execution vulnerability (CWE-94) on the server where the product is running.


Arbitrary PHP code may be executed on the server where the product is running.


Consider stop using mailform version 1.04
Since the developer was unreachable, existence of any mitigations is unknown.

Vendor Opinion

None provided

JPCERT/CC Addendum

During the meeting of Committee for authorizing the disclosure of unresolved vulnerabilities held on January 16, 2020, it was judged that an advisory for this vulnerability shall be disclosed since all the criteria and conditions described below which are stated in Standards for Handling Vulnerability related Information of Software Products and Other and Information Security Early Warning Partnership Guideline have been satisfied.

  1. The developer of the product is unreachable:
    JPCERT/CC had tried to reach the developer for a period of time (more than 6 months) however there were no responses from the developer. Therefore the committee reached the conclusion that it is reasonable and appropriate to judge the developer is unreachable.

    - The developer's contact information was not found online. Thus JPCERT/CC contacted Vector where the product was distributed on its website, and it was found that Vector was unable to reach the developer (September 28, 2015)
    - No response to disclosure of the developer's name (listed on March 25, 2016) on "List of unreachable developers"
    - No response to disclosure of the product name and its version (listed on June 24, 2016) on "Information Request"

  2. Existence of vulnerability has been verified:
    It was verified that the product contains a PHP code execution vulnerability by IPA.  Arbitrary PHP code execution on the server where the product runs was confirmed which violates the "Confidentiality" of the product.  For verification details, refer to the “Verification” section.

  3. Not disclosing this case may result in the risk that product users will have no means to know of the existence of the vulnerability in the product:
    Mitigations for this vulnerability are yet undisclosed by the developer, and it is unable to confirm the developer's grasp of all users of the product.
    It was determined that disclosure of this vulnerability is legitimate under these conditions.

  4. There are no particular reasons that would make disclosure inappropriate:
    After considering the developer’s stance and the risk to product users, the committee has judged that there are no particular reasons that would make disclosure inappropriate or that disclosure may cause any other issues.

Vulnerability Analysis by JPCERT/CC

Base Score: 7.3
Attack Vector(AV) Physical (P) Local (L) Adjacent (A) Network (N)
Attack Complexity(AC) High (H) Low (L)
Privileges Required(PR) High (H) Low (L) None (N)
User Interaction(UI) Required (R) None (N)
Scope(S) Unchanged (U) Changed (C)
Confidentiality Impact(C) None (N) Low (L) High (H)
Integrity Impact(I) None (N) Low (L) High (H)
Availability Impact(A) None (N) Low (L) High (H)
Base Score: 7.5
Access Vector(AV) Local (L) Adjacent Network (A) Network (N)
Access Complexity(AC) High (H) Medium (M) Low (L)
Authentication(Au) Multiple (M) Single (S) None (N)
Confidentiality Impact(C) None (N) Partial (P) Complete (C)
Integrity Impact(I) None (N) Partial (P) Complete (C)
Availability Impact(A) None (N) Partial (P) Complete (C)


The vulnerability was reported to IPA and its existence was confirmed by IPA.

Date of validation
・August 9, 2019

Validation environment (Server, Client, Product version 1.04)
・Microsoft Windows 10 Pro (64-bit) 1903/18362.267
・Apache 2.4.16
・PHP 5.6.11
・mailform 1.04
・Microsoft Edge 44.18362.267.0

Validation result
・The reproducibility confirmed on the server where the product is running


Other Information

JPCERT Reports
CERT Advisory
CPNI Advisory
CVE CVE-2020-5553
JVN iPedia JVNDB-2020-000901