From 7e0435546230ecebe3bfe1ac27eb0186c702c509 Mon Sep 17 00:00:00 2001 From: "Steven M. Schweda" Date: Sat, 15 Jun 2019 18:13:11 -0700 Subject: [PATCH] Fix CVE-2016-9844, buffer overflow in zipinfo --- zipinfo.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/zipinfo.c b/zipinfo.c index 5e77018..0be3e5b 100644 --- a/zipinfo.c +++ b/zipinfo.c @@ -1921,7 +1921,18 @@ static int zi_short(__G) /* return PK-type error code */ ush dnum=(ush)((G.crec.general_purpose_bit_flag>>1) & 3); methbuf[3] = dtype[dnum]; } else if (methnum >= NUM_METHODS) { /* unknown */ - sprintf(&methbuf[1], "%03u", G.crec.compression_method); + /* 2016-12-05 SMS. + * https://launchpad.net/bugs/1643750 + * Unexpectedly large compression methods overflow + * &methbuf[]. Use the old, three-digit decimal format + * for values which fit. Otherwise, sacrifice the "u", + * and use four-digit hexadecimal. + */ + if (G.crec.compression_method <= 999) { + sprintf( &methbuf[ 1], "%03u", G.crec.compression_method); + } else { + sprintf( &methbuf[ 0], "%04X", G.crec.compression_method); + } } for (k = 0; k < 15; ++k) -- 2.20.1