CWE-22 (对路径名的限制不恰当(路径遍历)) — Vulnerability Class 5195

5195 vulnerabilities classified as CWE-22 (对路径名的限制不恰当(路径遍历)). AI Chinese analysis included.

CWE-22 represents a critical input validation weakness where software fails to properly sanitize external input before constructing file paths. Attackers typically exploit this vulnerability by injecting directory traversal sequences, such as “../”, into user-supplied parameters. These malicious inputs allow the application to resolve file references outside the intended restricted directory, potentially granting unauthorized access to sensitive system files, configuration data, or source code. To mitigate this risk, developers must implement rigorous input validation techniques, ensuring that all path components are strictly checked against allowed characters and structures. Additionally, employing canonicalization to resolve symbolic links and relative paths before validation, combined with strict chroot jails or sandboxing, effectively confines file operations to designated directories, thereby neutralizing the potential for path traversal attacks and preserving system integrity.

MITRE CWE Description

The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. Many file operations are intended to take place within a restricted directory. By using special elements such as ".." and "/" separators, attackers can escape outside of the restricted location to access files or directories that are elsewhere on the system. One of the most common special elements is the "../" sequence, which in most modern operating systems is interpreted as the parent directory of the current location. This is referred to as relative path traversal. Path traversal also covers the use of absolute pathnames such as "/usr/local/bin" to access unexpected files. This is referred to as absolute path traversal.

Common Consequences (4)

Integrity, Confidentiality, Availability Execute Unauthorized Code or Commands

The attacker may be able to create or overwrite critical files that are used to execute code, such as programs or libraries.

Integrity Modify Files or Directories

The attacker may be able to overwrite or create critical files, such as programs, libraries, or important data. If the targeted file is used for a security mechanism, then the attacker may be able to bypass that mechanism. For example, appending a new account at the end of a password file may allow …

Confidentiality Read Files or Directories

The attacker may be able read the contents of unexpected files and expose sensitive data. If the targeted file is used for a security mechanism, then the attacker may be able to bypass that mechanism. For example, by reading a password file, the attacker could conduct brute force password guessing a…

Availability DoS: Crash, Exit, or Restart

The attacker may be able to overwrite, delete, or corrupt unexpected critical files such as programs, libraries, or important data. This may prevent the product from working at all and in the case of protection mechanisms such as authentication, it has the potential to lock out product users.

Mitigations (5)

Implementation Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range…

Architecture and Design For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.

Implementation Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked. Use a built-in path canonicalization function (such as realpath(…

Architecture and Design Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482].

Operation Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].

Effectiveness: Moderate

Examples (2)

The following code could be for a social networking application in which each user's profile information is stored in a separate file. All files are stored in a single directory.

my $dataPath = "/users/cwe/profiles"; my $username = param("user"); my $profilePath = $dataPath . "/" . $username; open(my $fh, "<", $profilePath) || ExitError("profile read error: $profilePath"); print "<ul>\n"; while (<$fh>) { print "<li>$_</li>\n"; } print "</ul>\n";

Bad · Perl

../../../etc/passwd

Attack

In the example below, the path to a dictionary file is read from a system property and used to initialize a File object.

String filename = System.getProperty("com.domain.application.dictionaryFile"); File dictionaryFile = new File(filename);

Bad · Java

CVE ID	Title	CVSS	Severity	Published
CVE-2019-1854	Cisco Expressway Series Directory Traversal Vulnerability — Cisco Expressway	4.3	-	2019-05-03
CVE-2019-1836	Cisco Nexus 9000 Series Fabric Switches Application Centric Infrastructure Mode Symbolic Link Path Traversal Vulnerability — Cisco NX-OS Software for Nexus 9000 Series Fabric Switches ACI Mode	7.1	-	2019-05-03
CVE-2019-5624	Rapid7 Metasploit Framework Zip Import Directory Traversal — Metasploit Framework	7.3	-	2019-04-30
CVE-2019-3902	Mercurial 后置链接漏洞 — mercurial	7.5	-	2019-04-22
CVE-2019-1835	Cisco Aironet Series Access Points Directory Traversal Vulnerability — Cisco Aironet Access Point Software	4.4	-	2019-04-18
CVE-2019-10242	Eclipse Kura 路径遍历漏洞 — Eclipse Kura	5.3	-	2019-04-09
CVE-2019-3880	Samba 路径遍历漏洞 — samba	4.3	-	2019-04-09
CVE-2014-5436	Honeywell International Experion PKS 路径遍历漏洞 — Experion PKS	7.5	-	2019-04-08
CVE-2019-5423	http-live-simulator 路径遍历漏洞 — http-live-simulator	7.5	-	2019-04-03
CVE-2019-5418	Action View 信息泄露漏洞 — https://github.com/rails/rails	7.5	-	2019-03-27
CVE-2019-3828	Ansible fetch module 路径遍历漏洞 — Ansible	3.2	-	2019-03-27
CVE-2019-1765	Cisco IP Phone 8800 Series Path Traversal Vulnerability — Cisco Wireless IP Phone 8821 and 8821-EX	6.5	-	2019-03-22
CVE-2019-5416	localhost-now npm package 安全漏洞 — localhost-now	7.5	-	2019-03-17
CVE-2019-3816	Openwsman 路径遍历漏洞 — openwsman	7.5	-	2019-03-14
CVE-2019-3474	Path traversal vulnerability in Filr web application — Filr	6.5	-	2019-02-20
CVE-2018-16479	http-live-simulator 路径遍历漏洞 — http-live-simulator	7.5	-	2019-02-01
CVE-2018-16482	node module mcstatic 路径遍历漏洞 — mcstatic	7.5	-	2019-02-01
CVE-2018-16485	m-server 路径遍历漏洞 — m-server	7.5	-	2019-02-01
CVE-2018-19003	多款GE产品路径遍历漏洞 — GE Mark VIe, EX2100e, EX2100e_Reg, and LS2100e	7.5	-	2018-12-14
CVE-2018-13812	多款Siemens产品路径遍历漏洞 — SIMATIC HMI Comfort Panels 4" - 22", SIMATIC HMI Comfort Outdoor Panels 7" & 15", SIMATIC HMI KTP Mobile Panels KTP400F, KTP700, KTP700F, KTP900 und KTP900F, SIMATIC WinCC Runtime Advanced, SIMATIC WinCC Runtime Professional, SIMATIC WinCC (TIA Portal), SIMATIC HMI Classic Devices (TP/MP/OP/MP Mobile Panel)	9.1	-	2018-12-13
CVE-2018-16478	simplehttpserver 路径遍历漏洞 — simplehttpserver	2.7	-	2018-12-04
CVE-2018-17934	NUUO CMS 安全漏洞 — NUUO CMS	9.8	-	2018-11-27
CVE-2018-16473	takeapeek module 路径遍历漏洞 — takeapeek	5.3	-	2018-11-06
CVE-2018-16475	Knightjs 路径遍历漏洞 — knightjs	7.5	-	2018-11-06
CVE-2018-14654	Red Hat Gluster 路径遍历漏洞 — glusterfs	6.5	-	2018-10-31
CVE-2018-14806	Advantech WebAccess 路径遍历漏洞 — Advantech WebAccess	9.8	-	2018-10-23
CVE-2018-0420	Cisco Wireless LAN Controller Software Directory Traversal Vulnerability — Cisco Wireless LAN Controller (WLC)	6.5	-	2018-10-17
CVE-2018-17899	LAquis SCADA 路径遍历漏洞 — LAquis SCADA	8.8	-	2018-10-17
CVE-2018-0405	Cisco RV180W Wireless-N Multifunction VPN Router Directory Path Traversal Vulnerability — Cisco RV180W Wireless-N Multifunction VPN Router	7.5	-	2018-10-05
CVE-2018-0464	Cisco Data Center Network Manager Path Traversal Vulnerability — Cisco Data Center Network Manager	8.1	-	2018-10-05

Vulnerabilities classified as CWE-22 (对路径名的限制不恰当(路径遍历)) represent 5195 CVEs. The CWE taxonomy describes the weakness; review individual CVEs for product-specific impact.