CVE-2007-4897 in Ekiga
Summary
by MITRE
pwlib, as used by Ekiga 2.0.5 and possibly other products, allows remote attackers to cause a denial of service (application crash) via a long argument to the PString::vsprintf function, related to a "memory management flaw". NOTE: this issue was originally reported as being in the SIPURL::GetHostAddress function in Ekiga (formerly GnomeMeeting).
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Analysis
by VulDB Data Team • 06/04/2025
The vulnerability identified as CVE-2007-4897 represents a critical memory management flaw within the pwlib library that serves as a foundational component for several VoIP applications including Ekiga 2.0.5. This issue manifests when the PString::vsprintf function receives an excessively long argument, leading to unpredictable application behavior and ultimately resulting in a complete denial of service condition. The flaw operates at the core level of string processing within the library, making it particularly dangerous as it can compromise the stability of any application that relies on this particular codebase for communication handling. The vulnerability was originally identified in the SIPURL::GetHostAddress function within Ekiga, which later evolved into a broader issue affecting the underlying pwlib library itself.
The technical exploitation of this vulnerability occurs through a buffer overflow condition that arises from improper memory allocation and handling within the PString::vsprintf implementation. When an attacker crafts a maliciously long argument to be processed by this function, the memory management system fails to properly handle the excessive data size, leading to stack corruption or heap overflow conditions. This type of flaw falls under the CWE-121 category of stack-based buffer overflow, where insufficient bounds checking allows memory to be overwritten beyond allocated buffers. The vulnerability demonstrates characteristics consistent with improper input validation and inadequate memory management practices that have been documented in numerous security advisories over the years.
The operational impact of this vulnerability extends beyond simple application crashes to potentially compromise the entire communication infrastructure that relies on affected applications. In enterprise environments where VoIP systems are critical for business operations, such a flaw could result in significant service disruption and potential security implications. Attackers could repeatedly exploit this vulnerability to maintain persistent denial of service conditions, effectively rendering VoIP services unusable for legitimate users. The vulnerability's presence in pwlib means that any software product utilizing this library, including but not limited to Ekiga, would be susceptible to similar exploitation attempts. This creates a widespread impact across multiple applications that share the same underlying codebase.
Mitigation strategies for this vulnerability should focus on immediate patching of the affected pwlib library to address the memory management flaw in the PString::vsprintf function. Organizations should prioritize updating their Ekiga installations and any other applications that depend on this library to versions that contain fixed implementations of the vulnerable function. Additionally, network-level defenses such as implementing input validation controls and monitoring for unusual argument lengths could provide additional layers of protection. Security practitioners should also consider implementing application whitelisting policies that restrict the execution of vulnerable applications until proper patches are deployed. The remediation process must include thorough testing of patched versions to ensure that the fix does not introduce regressions in functionality while effectively addressing the memory management issue that leads to the denial of service condition. This vulnerability highlights the importance of proper memory management practices and input validation in security-critical applications, particularly those handling real-time communication protocols.