Bash 语言 漏洞修复脚本技巧

Bash 语言漏洞修复脚本技巧

Bash（Bourne-Again SHell）是Linux和Unix系统中常用的命令行解释器，它提供了强大的脚本编写能力。由于历史原因和设计上的缺陷，Bash存在一些安全漏洞，如Shellshock（CVE-2014-6271）。本文将围绕Bash语言漏洞修复脚本技巧展开，旨在帮助开发者编写更安全、可靠的Bash脚本。

Bash 漏洞概述

Shellshock 是一个影响 Bash 的严重漏洞，它允许攻击者通过环境变量执行任意命令。这个漏洞的根源在于 Bash 的 `env` 和 `set` 命令处理 `()` 语法时的缺陷。攻击者可以通过构造特定的环境变量值来触发这个漏洞。

修复 Bash 漏洞的脚本技巧

1. 使用安全版本的 Bash

确保你的系统使用的是安全版本的 Bash。大多数现代 Linux 发行版已经修复了 Shellshock 漏洞，但仍然建议检查并更新到最新版本。

bash
检查 Bash 版本
bash --version

更新 Bash 到最新版本（以 Ubuntu 为例）
sudo apt-get update
sudo apt-get install bash


2. 限制环境变量

在 Bash 脚本中，尽量避免使用 `env` 和 `set` 命令，并限制环境变量的使用。以下是一些限制环境变量的技巧：

```bash
限制环境变量
export -n PATH
export -n LD_LIBRARY_PATH
export -n LIBRARY_PATH
export -n CPATH
export -n CFLAGS
export -n CXXFLAGS
export -n MACHTYPE
export -n CC
export -n CXX
export -n CPPFLAGS
export -n LDFLAGS
export -n NM
export -n RANLIB
export -n STRIP
export -n AR
export -n AS
export -n CCAS
export -n CXXAS
export -n CC1
export -n CXX1
export -n CC1PLUS
export -n CXX1PLUS
export -n CC2
export -n CXX2
export -n CC2PLUS
export -n CXX2PLUS
export -n CC3
export -n CXX3
export -n CC3PLUS
export -n CXX3PLUS
export -n CC4
export -n CXX4
export -n CC4PLUS
export -n CXX4PLUS
export -n CC5
export -n CXX5
export -n CC5PLUS
export -n CXX5PLUS
export -n CC6
export -n CXX6
export -n CC6PLUS
export -n CXX6PLUS
export -n CC7
export -n CXX7
export -n CC7PLUS
export -n CXX7PLUS
export -n CC8
export -n CXX8
export -n CC8PLUS
export -n CXX8PLUS
export -n CC9
export -n CXX9
export -n CC9PLUS
export -n CXX9PLUS
export -n CC10
export -n CXX10
export -n CC10PLUS
export -n CXX10PLUS
export -n CC11
export -n CXX11
export -n CC11PLUS
export -n CXX11PLUS
export -n CC12
export -n CXX12
export -n CC12PLUS
export -n CXX12PLUS
export -n CC13
export -n CXX13
export -n CC13PLUS
export -n CXX13PLUS
export -n CC14
export -n CXX14
export -n CC14PLUS
export -n CXX14PLUS
export -n CC15
export -n CXX15
export -n CC15PLUS
export -n CXX15PLUS
export -n CC16
export -n CXX16
export -n CC16PLUS
export -n CXX16PLUS
export -n CC17
export -n CXX17
export -n CC17PLUS
export -n CXX17PLUS
export -n CC18
export -n CXX18
export -n CC18PLUS
export -n CXX18PLUS
export -n CC19
export -n CXX19
export -n CC19PLUS
export -n CXX19PLUS
export -n CC20
export -n CXX20
export -n CC20PLUS
export -n CXX20PLUS
export -n CC21
export -n CXX21
export -n CC21PLUS
export -n CXX21PLUS
export -n CC22
export -n CXX22
export -n CC22PLUS
export -n CXX22PLUS
export -n CC23
export -n CXX23
export -n CC23PLUS
export -n CXX23PLUS
export -n CC24
export -n CXX24
export -n CC24PLUS
export -n CXX24PLUS
export -n CC25
export -n CXX25
export -n CC25PLUS
export -n CXX25PLUS
export -n CC26
export -n CXX26
export -n CC26PLUS
export -n CXX26PLUS
export -n CC27
export -n CXX27
export -n CC27PLUS
export -n CXX27PLUS
export -n CC28
export -n CXX28
export -n CC28PLUS
export -n CXX28PLUS
export -n CC29
export -n CXX29
export -n CC29PLUS
export -n CXX29PLUS
export -n CC30
export -n CXX30
export -n CC30PLUS
export -n CXX30PLUS
export -n CC31
export -n CXX31
export -n CC31PLUS
export -n CXX31PLUS
export -n CC32
export -n CXX32
export -n CC32PLUS
export -n CXX32PLUS
export -n CC33
export -n CXX33
export -n CC33PLUS
export -n CXX33PLUS
export -n CC34
export -n CXX34
export -n CC34PLUS
export -n CXX34PLUS
export -n CC35
export -n CXX35
export -n CC35PLUS
export -n CXX35PLUS
export -n CC36
export -n CXX36
export -n CC36PLUS
export -n CXX36PLUS
export -n CC37
export -n CXX37
export -n CC37PLUS
export -n CXX37PLUS
export -n CC38
export -n CXX38
export -n CC38PLUS
export -n CXX38PLUS
export -n CC39
export -n CXX39
export -n CC39PLUS
export -n CXX39PLUS
export -n CC40
export -n CXX40
export -n CC40PLUS
export -n CXX40PLUS
export -n CC41
export -n CXX41
export -n CC41PLUS
export -n CXX41PLUS
export -n CC42
export -n CXX42
export -n CC42PLUS
export -n CXX42PLUS
export -n CC43
export -n CXX43
export -n CC43PLUS
export -n CXX43PLUS
export -n CC44
export -n CXX44
export -n CC44PLUS
export -n CXX44PLUS
export -n CC45
export -n CXX45
export -n CC45PLUS
export -n CXX45PLUS
export -n CC46
export -n CXX46
export -n CC46PLUS
export -n CXX46PLUS
export -n CC47
export -n CXX47
export -n CC47PLUS
export -n CXX47PLUS
export -n CC48
export -n CXX48
export -n CC48PLUS
export -n CXX48PLUS
export -n CC49
export -n CXX49
export -n CC49PLUS
export -n CXX49PLUS
export -n CC50
export -n CXX50
export -n CC50PLUS
export -n CXX50PLUS
export -n CC51
export -n CXX51
export -n CC51PLUS
export -n CXX51PLUS
export -n CC52
export -n CXX52
export -n CC52PLUS
export -n CXX52PLUS
export -n CC53
export -n CXX53
export -n CC53PLUS
export -n CXX53PLUS
export -n CC54
export -n CXX54
export -n CC54PLUS
export -n CXX54PLUS
export -n CC55
export -n CXX55
export -n CC55PLUS
export -n CXX55PLUS
export -n CC56
export -n CXX56
export -n CC56PLUS
export -n CXX56PLUS
export -n CC57
export -n CXX57
export -n CC57PLUS
export -n CXX57PLUS
export -n CC58
export -n CXX58
export -n CC58PLUS
export -n CXX58PLUS
export -n CC59
export -n CXX59
export -n CC59PLUS
export -n CXX59PLUS
export -n CC60
export -n CXX60
export -n CC60PLUS
export -n CXX60PLUS
export -n CC61
export -n CXX61
export -n CC61PLUS
export -n CXX61PLUS
export -n CC62
export -n CXX62
export -n CC62PLUS
export -n CXX62PLUS
export -n CC63
export -n CXX63
export -n CC63PLUS
export -n CXX63PLUS
export -n CC64
export -n CXX64
export -n CC64PLUS
export -n CXX64PLUS
export -n CC65
export -n CXX65
export -n CC65PLUS
export -n CXX65PLUS
export -n CC66
export -n CXX66
export -n CC66PLUS
export -n CXX66PLUS
export -n CC67
export -n CXX67
export -n CC67PLUS
export -n CXX67PLUS
export -n CC68
export -n CXX68
export -n CC68PLUS
export -n CXX68PLUS
export -n CC69
export -n CXX69
export -n CC69PLUS
export -n CXX69PLUS
export -n CC70
export -n CXX70
export -n CC70PLUS
export -n CXX70PLUS
export -n CC71
export -n CXX71
export -n CC71PLUS
export -n CXX71PLUS
export -n CC72
export -n CXX72
export -n CC72PLUS
export -n CXX72PLUS
export -n CC73
export -n CXX73
export -n CC73PLUS
export -n CXX73PLUS
export -n CC74
export -n CXX74
export -n CC74PLUS
export -n CXX74PLUS
export -n CC75
export -n CXX75
export -n CC75PLUS
export -n CXX75PLUS
export -n CC76
export -n CXX76
export -n CC76PLUS
export -n CXX76PLUS
export -n CC77
export -n CXX77
export -n CC77PLUS
export -n CXX77PLUS
export -n CC78
export -n CXX78
export -n CC78PLUS
export -n CXX78PLUS
export -n CC79
export -n CXX79
export -n CC79PLUS
export -n CXX79PLUS
export -n CC80
export -n CXX80
export -n CC80PLUS
export -n CXX80PLUS
export -n CC81
export -n CXX81
export -n CC81PLUS
export -n CXX81PLUS
export -n CC82
export -n CXX82
export -n CC82PLUS
export -n CXX82PLUS
export -n CC83
export -n CXX83
export -n CC83PLUS
export -n CXX83PLUS
export -n CC84
export -n CXX84
export -n CC84PLUS
export -n CXX84PLUS
export -n CC85
export -n CXX85
export -n CC85PLUS
export -n CXX85PLUS
export -n CC86
export -n CXX86
export -n CC86PLUS
export -n CXX86PLUS
export -n CC87
export -n CXX87
export -n CC87PLUS
export -n CXX87PLUS
export -n CC88
export -n CXX88
export -n CC88PLUS
export -n CXX88PLUS
export -n CC89
export -n CXX89
export -n CC89PLUS
export -n CXX89PLUS
export -n CC90
export -n CXX90
export -n CC90PLUS
export -n CXX90PLUS
export -n CC91
export -n CXX91
export -n CC91PLUS
export -n CXX91PLUS
export -n CC92
export -n CXX92
export -n CC92PLUS
export -n CXX92PLUS
export -n CC93
export -n CXX93
export -n CC93PLUS
export -n CXX93PLUS
export -n CC94
export -n CXX94
export -n CC94PLUS
export -n CXX94PLUS
export -n CC95
export -n CXX95
export -n CC95PLUS
export -n CXX95PLUS
export -n CC96
export -n CXX96
export -n CC96PLUS
export -n CXX96PLUS
export -n CC97
export -n CXX97
export -n CC97PLUS
export -n CXX97PLUS
export -n CC98
export -n CXX98
export -n CC98PLUS
export -n CXX98PLUS
export -n CC99
export -n CXX99
export -n CC99PLUS
export -n CXX99PLUS
export -n CC100
export -n CXX100
export -n CC100PLUS
export -n CXX100PLUS
export -n CC101
export -n CXX101
export -n CC101PLUS
export -n CXX101PLUS
export -n CC102
export -n CXX102
export -n CC102PLUS
export -n CXX102PLUS
export -n CC103
export -n CXX103
export -n CC103PLUS
export -n CXX103PLUS
export -n CC104
export -n CXX104
export -n CC104PLUS
export -n CXX104PLUS
export -n CC105
export -n CXX105
export -n CC105PLUS
export -n CXX105PLUS
export -n CC106
export -n CXX106
export -n CC106PLUS
export -n CXX106PLUS
export -n CC107
export -n CXX107
export -n CC107PLUS
export -n CXX107PLUS
export -n CC108
export -n CXX108
export -n CC108PLUS
export -n CXX108PLUS
export -n CC109
export -n CXX109
export -n CC109PLUS
export -n CXX109PLUS
export -n CC110
export -n CXX110
export -n CC110PLUS
export -n CXX110PLUS
export -n CC111
export -n CXX111
export -n CC111PLUS
export -n CXX111PLUS
export -n CC112
export -n CXX112
export -n CC112PLUS
export -n CXX112PLUS
export -n CC113
export -n CXX113
export -n CC113PLUS
export -n CXX113PLUS
export -n CC114
export -n CXX114
export -n CC114PLUS
export -n CXX114PLUS
export -n CC115
export -n CXX115
export -n CC115PLUS
export -n CXX115PLUS
export -n CC116
export -n CXX116
export -n CC116PLUS
export -n CXX116PLUS
export -n CC117
export -n CXX117
export -n CC117PLUS
export -n CXX117PLUS
export -n CC118
export -n CXX118
export -n CC118PLUS
export -n CXX118PLUS
export -n CC119
export -n CXX119
export -n CC119PLUS
export -n CXX119PLUS
export -n CC120
export -n CXX120
export -n CC120PLUS
export -n CXX120PLUS
export -n CC121
export -n CXX121
export -n CC121PLUS
export -n CXX121PLUS
export -n CC122
export -n CXX122
export -n CC122PLUS
export -n CXX122PLUS
export -n CC123
export -n CXX123
export -n CC123PLUS
export -n CXX123PLUS
export -n CC124
export -n CXX124
export -n CC124PLUS
export -n CXX124PLUS
export -n CC125
export -n CXX125
export -n CC125PLUS
export -n CXX125PLUS
export -n CC126
export -n CXX126
export -n CC126PLUS
export -n CXX126PLUS
export -n CC127
export -n CXX127
export -n CC127PLUS
export -n CXX127PLUS
export -n CC128
export -n CXX128
export -n CC128PLUS
export -n CXX128PLUS
export -n CC129
export -n CXX129
export -n CC129PLUS
export -n CXX129PLUS
export -n CC130
export -n CXX130
export -n CC130PLUS
export -n CXX130PLUS
export -n CC131
export -n CXX131
export -n CC131PLUS
export -n CXX