On Wed, Apr 17, 2024 at 02:36:02PM -0300, Adhemerval Zanella Netto wrote: > GLIBC-SA-2024-0004: > =================== > ISO-2022-CN-EXT: fix out-of-bound writes when writing escape sequence > > The iconv() function in the GNU C Library versions 2.39 and older may > overflow the output buffer passed to it by up to 4 bytes when converting > strings to the ISO-2022-CN-EXT character set, which may be used to > crash an application or overwrite a neighbouring variable. > > ISO-2022-CN-EXT uses escape sequences to indicate character set changes > (as specified by RFC 1922). While the SOdesignation has the expected > bounds checks, neither SS2designation nor SS3designation have its; > allowing a write overflow of 1, 2, or 3 bytes with fixed values: > '$+I', '$+J', '$+K', '$+L', '$+M', or '$*H'. > > CVE-Id: CVE-2024-2961 > Public-Date: 2024-04-17 > Vulnerable-Commit: 755104edc75c53f4a0e7440334e944ad3c6b32fc (2.1.93-169) > Fix-Commit: f9dc609e06b1136bb0408be9605ce7973a767ada (2.40) > Fix-Commit: 31da30f23cddd36db29d5b6a1c7619361b271fb4 (2.39-31) > Fix-Commit: e1135387deded5d73924f6ca20c72a35dc8e1bda (2.38-66) > Fix-Commit: 89ce64b269a897a7780e4c73a7412016381c6ecf (2.37-89) > Fix-Commit: 4ed98540a7fd19f458287e783ae59c41e64df7b5 (2.36-164) > Fix-Commit: 36280d1ce5e245aabefb877fe4d3c6cff95dabfa (2.35-315) > Fix-Commit: a8b0561db4b9847ebfbfec20075697d5492a363c (2.34-459) > Fix-Commit: ed4f16ff6bed3037266f1fa682ebd32a18fce29c (2.33-263) > Fix-Commit: 682ad4c8623e611a971839990ceef00346289cc9 (2.32-140) > > Reported-By: Charles Fol
I hope Charles will share further detail with oss-security in due time, but meanwhile his upcoming OffensiveCon talk abstract reveals a bit: https://www.offensivecon.org/speakers/2024/charles-fol.html > CHARLES FOL > ICONV, SET THE CHARSET TO RCE: EXPLOITING THE GLIBC TO HACK THE PHP ENGINE > > Abstract > A few months ago, I stumbled upon a 24 years old buffer overflow in the > glibc. Despite being reachable in multiple well-known libraries or > programs, it proved rarely exploitable. Indeed, this was not a foos bug: > with hard-to-achieve preconditions, it did not even provide a nice > primitive. On PHP however, it lead to amazing results: a new > exploitation technique that affects the whole PHP ecosystem, and the > compromission of several applications. > > This talk will first walk you through the discovery of the bug and its > limitations, before describing the conception of several remote binary > PHP exploits, and through them offer unique insight in the internal of > the engine of the web language, and the difficulties one faces when > exploiting it. > > BIO > Charles Fol, also known as cfreal, is a security researcher at LEXFO / > AMBIONICS. He has discovered remote code execution vulnerabilities > targeting renowned CMS and frameworks such as Drupal, Magento, Symfony > or Laravel, but also enjoys binary exploitation, to escalate privileges > (Apache, PHP-FPM) or compromise security solutions (DataDog's Sqreen, > Fortinet SSL VPN, Watchguard). He is the creator for PHPGGC, the go-to > tool to exploit PHP deserialization, and an expert in PHP internals. The event is on May 10-11th, so in 3 weeks from now. Alexander
