CVE-2017-20250: Mac Photo Gallery 3.0 Path Traversal File Download Vulnerability

Technical summary

CVE-2017-20250 is a CWE-22 path traversal vulnerability affecting Mac Photo Gallery 3.0. The vulnerability exists in the macdownload.php endpoint, which fails to properly validate or sanitize the albid parameter before using it to construct file paths. An attacker can inject directory traversal sequences (../) to traverse beyond the intended plugin directory structure and access arbitrary files readable by the web server process. The lack of access controls on this endpoint means any remote, unauthenticated caller can send requests. No user interaction or elevated privileges are required for exploitation.

Business impact

This vulnerability poses a direct risk to confidentiality. An attacker can exfiltrate sensitive application and server files, including WordPress configuration files that may contain database credentials, API keys, authentication tokens, and other secrets. Compromise of such credentials can lead to lateral movement, unauthorized database access, or further infrastructure compromise. Organizations running Mac Photo Gallery 3.0 should assume that any secret material stored in accessible file paths may be exposed, requiring immediate credential rotation for any compromised accounts or API keys.

Affected systems

Mac Photo Gallery version 3.0 is affected. Organizations using this plugin should inventory instances and plan immediate remediation. The vulnerability affects the web-accessible macdownload.php file; exposure depends on whether the plugin is deployed and whether the webroot and file permissions allow the web server process to read sensitive configuration files. Any WordPress installation running Mac Photo Gallery 3.0 should be considered at risk.

Exploitability

This vulnerability is straightforward to exploit. An attacker needs only to craft HTTP requests to the macdownload.php endpoint with path traversal sequences in the albid parameter—no special tools, authentication, or user interaction required. The attack is network-accessible and works over standard HTTP/HTTPS. This combination of factors (network-accessible, unauthenticated, no user interaction, simple payload construction) results in a CVSS 3.1 score of 7.5 (High severity), reflecting the direct threat to data confidentiality.

Remediation

Immediately update Mac Photo Gallery to a patched version that validates and sanitizes the albid parameter and enforces proper path restrictions. Verify the patched version against the vendor advisory. In parallel, rotate any secrets (database passwords, API keys, authentication tokens) that may have been exposed or are stored in files accessible via the plugin directory. Review server access logs and file integrity monitoring records for evidence of exploitation. Implement input validation and path canonicalization controls in any custom download functionality.

Patch guidance

Contact the Mac Photo Gallery vendor or check their official repository for a patched version that addresses path traversal in the albid parameter handling. Apply the patch as soon as it becomes available. Until patching is possible, consider disabling the Mac Photo Gallery plugin if it is not critical to operations, or restrict access to the macdownload.php endpoint via web application firewall rules or network controls to trusted IP ranges only. Verify the patch against the vendor advisory to confirm the vulnerable parameter is properly sanitized.

Detection guidance

Monitor web server access logs for requests to macdownload.php that contain directory traversal sequences such as ../, ..\, %2e%2e%2f, or encoded variants in the albid parameter. Deploy web application firewall (WAF) rules to detect and block path traversal patterns in request parameters. Check file integrity monitoring systems for unexpected file access or reads of sensitive files like wp-load.php, wp-config.php, and other configuration files from the web server process. Review error logs for repeated failed download attempts. Intrusion detection systems can be tuned to flag suspicious access patterns to the plugin directory.

Why prioritize this

This vulnerability should receive immediate attention due to its High CVSS score (7.5), unauthenticated network exploitability, and direct risk to confidentiality of sensitive files. The simplicity of exploitation means attack likelihood is high. Any secrets stored in accessible configuration files are at direct risk. Organizations running Mac Photo Gallery 3.0 should prioritize patching or mitigation within days, not weeks.

Risk score, explained

The CVSS 3.1 score of 7.5 (High) reflects: (1) network-accessible attack vector requiring no authentication or user interaction; (2) low attack complexity—the vulnerability is trivial to exploit; (3) high impact on confidentiality—arbitrary file disclosure from the server; (4) no impact on integrity or availability. The absence of access controls, authentication, or user interaction elevates the severity despite the limited scope of impact (confidentiality only).

Frequently asked questions