CWE WEAKNESSES  /  CWE-130

CWE-130

Improper Handling of Length Parameter Inconsistency

What it is

The product parses a formatted message or structure, but it does not handle or incorrectly handles a length field that is inconsistent with the actual length of the associated data.

If an attacker can manipulate the length parameter associated with an input such that it is inconsistent with the actual length of the input, this can be leveraged to cause the target application to behave in unexpected, and possibly, malicious ways. One of the possible motives for doing so is to pass in arbitrarily large input to the application. Another possible motivation is the modification of application state by including invalid data for subsequent properties of the application. Such weaknesses commonly lead to attacks such as buffer overflows and execution of arbitrary code.

Impact

Mitigations

• [Implementation] When processing structured incoming data containing a size field followed by raw data, ensure that you identify and resolve any inconsistencies between the size field and the actual size of the data.
• [Implementation] Do not let the user control the size of the buffer.
• [Implementation] Validate that the length of the user-supplied data is consistent with the buffer size.

Real-world CVE examples

• CVE-2014-0160 — Chain: "Heartbleed" bug receives an inconsistent length parameter (CWE-130) enabling an out-of-bounds read (CWE-126), returning memory that could include privat
• CVE-2009-2299 — Web application firewall consumes excessive memory when an HTTP request contains a large Content-Length value but no POST data.
• CVE-2001-0825 — Buffer overflow in internal string handling routine allows remote attackers to execute arbitrary commands via a length argument of zero or less, which disables
• CVE-2001-1186 — Web server allows remote attackers to cause a denial of service via an HTTP request with a content-length value that is larger than the size of the request, whi
• CVE-2001-0191 — Service does not properly check the specified length of a cookie, which allows remote attackers to execute arbitrary commands via a buffer overflow, or brute fo
• CVE-2003-0429 — Traffic analyzer allows remote attackers to cause a denial of service and possibly execute arbitrary code via invalid IPv4 or IPv6 prefix lengths, possibly trig
• CVE-2000-0655 — Chat client allows remote attackers to cause a denial of service or execute arbitrary commands via a JPEG image containing a comment with an illegal field lengt
• CVE-2004-0492 — Server allows remote attackers to cause a denial of service and possibly execute arbitrary code via a negative Content-Length HTTP header field causing a heap-b
• CVE-2004-0201 — Help program allows remote attackers to execute arbitrary commands via a heap-based buffer overflow caused by a .CHM file with a large length field
• CVE-2003-0825 — Name services does not properly validate the length of certain packets, which allows attackers to cause a denial of service and possibly execute arbitrary code.
• CVE-2004-0095 — Policy manager allows remote attackers to cause a denial of service (memory consumption and crash) and possibly execute arbitrary code via an HTTP POST request
• CVE-2004-0826 — Heap-based buffer overflow in library allows remote attackers to execute arbitrary code via a modified record length field in an SSLv2 client hello message.

Related weaknesses

Source: MITRE CWE. View on cwe.mitre.org →