CVE-2007-3477 in GD Graphics Library
Summary
by MITRE
The (a) imagearc and (b) imagefilledarc functions in GD Graphics Library (libgd) before 2.0.35 allow attackers to cause a denial of service (CPU consumption) via a large (1) start or (2) end angle degree value.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 07/21/2019
The vulnerability identified as CVE-2007-3477 affects the GD Graphics Library, specifically targeting the imagearc and imagefilledarc functions within libgd versions prior to 2.0.35. This issue represents a classic denial of service vulnerability that exploits improper input validation mechanisms within the graphics processing functions. The flaw manifests when these functions receive excessively large angle degree values, causing the library to consume excessive CPU resources during processing. The vulnerability falls under the category of resource exhaustion attacks, where malicious input triggers computational overhead that can be exploited to disrupt service availability.
The technical implementation of this vulnerability stems from inadequate boundary checking within the angle parameter validation logic. When the start or end angle parameters exceed normal operational ranges, the affected functions enter into computationally expensive processing loops that can consume significant system resources. The flaw demonstrates characteristics consistent with CWE-129, which addresses improper validation of array indices and other input parameters, and more specifically aligns with CWE-400, addressing unspecified resource exhaustion conditions. The lack of proper input sanitization allows attackers to feed malformed angle values that cause the library to perform unnecessary calculations, leading to excessive CPU utilization.
From an operational impact perspective, this vulnerability creates significant security implications for systems that process untrusted image data through the GD library. Web applications, content management systems, and image processing services that rely on libgd for graphics manipulation become vulnerable to denial of service attacks. Attackers can exploit this weakness by submitting crafted image files containing extreme angle values, causing the target system to experience high CPU load and potentially complete service unavailability. The vulnerability's impact extends beyond simple resource exhaustion as it can affect system stability and availability, particularly in environments where multiple concurrent image processing requests occur. This type of attack pattern aligns with ATT&CK technique T1499.004, which covers network denial of service attacks through resource exhaustion.
The exploitation of this vulnerability requires minimal technical skill and can be automated, making it particularly dangerous in web environments where image uploads are common. Systems processing user-generated content become prime targets for this type of attack, as attackers can simply upload malicious images that trigger the vulnerable code path. The fix for this vulnerability involved implementing proper input validation and boundary checking for angle parameters within the affected functions, ensuring that angle values fall within acceptable ranges before processing. Organizations should prioritize updating their libgd installations to version 2.0.35 or later, as this release contains the necessary patches to prevent the excessive CPU consumption. Additionally, implementing input validation mechanisms at the application level can provide additional defense in depth, preventing malformed angle values from reaching the vulnerable library functions. The remediation process should include thorough testing of image processing workflows to ensure that the patch does not introduce compatibility issues while effectively addressing the resource exhaustion vulnerability.