Improper Handling of Length Parameter Inconsistency

Opis

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.

Inne nazwy

length manipulation

length tampering

Skutki

• Confidentiality, Integrity

  Read Memory; Modify Memory; Varies by Context

Zapobieganie

• 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.

Przykłady podatności

• 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 private cryptographic keys and other sensitive data.
• 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 the length check.
• 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, which prevents server from timing out the connection.
• 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 force authentication by using a short cookie length.
• 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 triggering a buffer overflow.
• 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 length of 1.
• 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-based buffer overflow.
• 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. Can overlap zero-length issues
• 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 with an invalid Content-Length value.
• 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.
• CVE-2004-0808 When domain logons are enabled, server allows remote attackers to cause a denial of service via a SAM_UAS_CHANGE request with a length value that is larger than the number of structures that are provided.
• CVE-2002-1357 Multiple SSH2 servers and clients do not properly handle packets or data elements with incorrect length specifiers, which may allow remote attackers to cause a denial of service or possibly execute arbitrary code.
• CVE-2004-0774 Server allows remote attackers to cause a denial of service (CPU and memory exhaustion) via a POST request with a Content-Length header set to -1.
• CVE-2004-0989 Multiple buffer overflows in xml library that may allow remote attackers to execute arbitrary code via long URLs.
• CVE-2004-0568 Application does not properly validate the length of a value that is saved in a session file, which allows remote attackers to execute arbitrary code via a malicious session file (.ht), web site, or Telnet URL contained in an e-mail message, triggering a buffer overflow.
• CVE-2003-0327 Server allows remote attackers to cause a denial of service via a remote password array with an invalid length, which triggers a heap-based buffer overflow.
• CVE-2003-0345 Product allows remote attackers to cause a denial of service and possibly execute arbitrary code via an SMB packet that specifies a smaller buffer length than is required.
• CVE-2004-0430 Server allows remote attackers to execute arbitrary code via a LoginExt packet for a Cleartext Password User Authentication Method (UAM) request with a PathName argument that includes an AFPName type string that is longer than the associated length field.
• CVE-2005-0064 PDF viewer allows remote attackers to execute arbitrary code via a PDF file with a large /Encrypt /Length keyLength value.
• CVE-2004-0413 SVN client trusts the length field of SVN protocol URL strings, which allows remote attackers to cause a denial of service and possibly execute arbitrary code via an integer overflow that leads to a heap-based buffer overflow.
• CVE-2004-0940 Is effectively an accidental double increment of a counter that prevents a length check conditional from exiting a loop.
• CVE-2002-1235 Length field of a request not verified.
• CVE-2005-3184 Buffer overflow by modifying a length value.

Słabość nadrzędna

• CWE-240 Improper Handling of Inconsistent Structural Elements
• CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

Może prowadzić do

• CWE-805 Buffer Access with Incorrect Length Value

Kiedy powstaje

• Implementation

Dotyczy

C, C++, Not Language-Specific, Not Technology-Specific

Uwagi

This probably overlaps other categories including zero-length issues.