CVE-2019-1010238 in SD-WAN Edge
Summary
by MITRE
Gnome Pango 1.42 and later is affected by: Buffer Overflow. The impact is: The heap based buffer overflow can be used to get code execution. The component is: function name: pango_log2vis_get_embedding_levels, assignment of nchars and the loop condition. The attack vector is: Bug can be used when application pass invalid utf-8 strings to functions like pango_itemize.
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Analysis
by VulDB Data Team • 05/16/2025
The vulnerability identified as CVE-2019-1010238 affects Gnome Pango version 1.42 and later, representing a critical heap-based buffer overflow that can potentially lead to remote code execution. This flaw resides within the pango_log2vis_get_embedding_levels function, where improper handling of input parameters creates exploitable conditions. The vulnerability manifests when applications process invalid utf-8 strings through functions such as pango_itemize, making it particularly dangerous in environments where user input or external data processing occurs. The buffer overflow vulnerability falls under CWE-121, which describes heap-based buffer overflow conditions, and represents a significant security risk as it can be leveraged by attackers to execute arbitrary code within the context of the affected application.
The technical implementation of this vulnerability occurs during the processing of Unicode text where the function pango_log2vis_get_embedding_levels fails to properly validate the number of characters in the input string. The flaw specifically involves the assignment of nchars variable and the loop condition that iterates through the character sequence, creating a scenario where memory allocation does not match the actual data processing requirements. When applications pass malformed utf-8 sequences to these functions, the buffer overflow occurs in the heap memory space, potentially allowing attackers to overwrite adjacent memory locations with malicious code. This type of vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as successful exploitation could enable attackers to execute arbitrary commands through the compromised application.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it provides attackers with the capability to achieve full system compromise through remote code execution. Applications utilizing Gnome Pango for text rendering, particularly those processing untrusted input from web browsers, email clients, or document viewers, become prime targets for exploitation. The vulnerability affects a wide range of software including web browsers, office suites, and desktop applications that rely on Pango for text layout and rendering operations. Attackers could leverage this flaw by crafting malicious utf-8 sequences that trigger the buffer overflow condition when processed by vulnerable applications, potentially leading to complete system compromise. The exploitation requires minimal privileges and can be executed through standard application interfaces, making it particularly dangerous in enterprise environments where multiple applications may be vulnerable.
Mitigation strategies for CVE-2019-1010238 should prioritize immediate patching of affected Gnome Pango installations to version 1.43.1 or later, which contains the necessary fixes for the buffer overflow condition. System administrators should implement input validation measures to sanitize utf-8 sequences before processing them through Pango functions, particularly in applications that handle external or user-provided content. Additionally, deploying runtime protections such as address space layout randomization and stack canaries can help mitigate exploitation attempts, though these measures do not address the root cause. Network-based protections including web application firewalls and content filtering systems should be configured to detect and block suspicious utf-8 sequences that may trigger the vulnerability. Organizations should also consider implementing application sandboxing and privilege separation techniques to limit the potential impact of successful exploitation attempts, ensuring that even if an attacker successfully exploits the vulnerability, they cannot gain unrestricted access to the underlying system. Regular security assessments and vulnerability scanning should be conducted to identify any remaining instances of vulnerable Pango versions within the organization's infrastructure.